For someone who was as physically dominant as Wilt relative to his peers, and as great of an offensive rebounder and finisher as Wilt was (as shown by his FG% when his teams stopped asking him for post scoring), a FG% of "only" around 50% is pretty low (combined with a TS% of under 55% and probably high TOV%). In the playoffs he's at only 52.4 TS% for his career. I don't doubt Wilt made a lot of those fadeaways, I doubt how efficient he was at making them. Just because you can show me footage of Karl Malone draining turnaround isolation jumpers from 15 feet doesn't mean he was efficient at making them...he just took a lot of them. But this is something I've stopped trying to argue with Wilt fans. I've read them say that his midrange game was comparable to a guy like KG, uh seems legit...considering he was one of the worst FT shooters in history.
On film, the offense looks predictable when he gets the ball. For example, watch game 7 of the '70 finals. I've seen his fans actually use this game as a "good" game by Wilt based on boxscore numbers (even put highlights of it on youtube) but look at how bad and predictable the offense is when it runs through him in the first half. Any time Wilt posts up it was either a bad shot, him drawing a foul but missing FTs (disrupts flow of offense and doesn't make defense pay for fouling) or a turnover. He was super efficient on finishes and offensive boards though (but barely converted any post up opportunities), and it kind of shows what I've thought about Wilt...he can have a nice game "FG%" wise but not be an efficient post up player. Doesn't it make sense WHY Hannum decided to not use Wilt as a post scorer anymore but mainly as a finisher/offensive rebounder? Maybe...he wasn't that efficient when used in that type of a role. It's why we don't see him make his teams great offensively during his volume scoring years despite what his boxscore numbers say.
On top of this, combined with how teams played back then, he slowed down the offense. His Warrior teammates even complained about this, how they felt "shackled" around him. Some people might find it difficult to understand, I know I did a few years ago, but you can look like a great scorer in the boxscore but not be making much of an offensive impact at all. He looks amazing on offensive boards and as a finisher, but his post offense doesn't look as efficient as guys like Shaq, Hakeem, KAJ and the like.
Here are two games from Wilt's prime years where every post up he made is included (not handpicked misses or makes):
The point isn't whether he made or missed the shots, those things vary game to game. But it's things like his awful footwork, how many dribbles he uses to make his move (this wouldn't fly in today's game where double teaming and trapping is waaay more common), his dribbles aren't fluid or in rhythm, his touch outside of 5+ feet away looks really awkward but it's pretty soft on his bank shot (though he is soo slow in getting into that move), has a bad habit of exposing the ball and he clearly doesn't have a lower base and center of gravity (long skinny legs) of a guy like Shaq to play the power game like him. These are things that are consistent on a game to game basis. But you guys can believe that a guy who was as horrible as Wilt at FTs had awesome midrange game. I just think it's a big leap of faith.
TL;DR: Wilt was an awesome finisher and awesome on the offensive boards but his post offense is very overrated. That combined with his historically bad FT shooting (and likely high propensity for turnovers) doesn't make him an efficient option in the post like his numbers would suggest.
Defensively, I've heard his fans compare his impact to Russell. Even at his best when he was motivated, I disagree with that strongly. He was a dominant shot blocker, a good man to man defender in the post in his later years and that's it. I've heard commentators point out how Wilt doesn't leave the paint and cover screen and rolls. Clearly doesn't have Russell's (or KG's or Hakeem's or Walton's) "horizontal" game. His defensive impact is inconsistent throughout his years. I see him defensively like I do Shaq. Great when he wants to be (though can be exploited by some weaknesses) but inconsistent effort wise. I'm pretty sure we have some data too of Wilt not improving offenses and defenses as much as you'd expect from someone with his boxscore numbers.
His year by year impact from team to team definitely doesn't say much in his favor either:
It's not just looking at one case of SRS dropping...his impact is questionable in a lot of years.
He put up 44/25 on a 31 win team in a season where he was healthy and played all games (also had two other all-star players on his team). How can you be that statistically and physically dominant and come out with such few wins? Then couple of years later, he was leading the Warriors to the worst record in the league at 11-27 in games he played, then he gets traded for peanuts, joins the Sixers who were 21-20 at the time they made the trade and finished 40-40. When Warriors made improvements next season, there are articles of Wilt's former Warrior teammates complaining about how "shackled" they were with Wilt on offense. Sixers of course became an all-time great team in a couple of years with Wilt literally being the last option on the floor scoring wise though improving other parts of his game (along with them adding guys like Billy C to the roster and guys like Chet Walker and Luke Jackson maturing).
Then he gets traded to the Lakers who were starving for a dominant center all decade and...nothing happens. The SRS of the team goes down from the previous year (despite West playing more games), they still lose to Boston in the finals and got lucky in that they didn't get knocked out in the first round by the Warriors (Mullins got injured). There are some absolutely scathing articles in LA newspapers at the time. Meanwhile Wilt's former team still wins 55 games and that is with their starting PF Luke Jackson basically missing the entire season. Then the following year, the Lakers still win 46 games (7-5 with Wilt, 38-31 without him...Baylor/West missed some of these games too). And the next year with Wilt playing all 82 games, they win 48. It should be noted that without West, Wilt leads the Lakers to an awful 3-10 record (the MOV of the Lakers over this stretch? -10.9) that year.
I'd like to think a top 5 player would show a little bit more impact than that over the years. This isn't one case of finding a "gotcha" incident, this is something we see over most of his career. Then there are major concerns about his playoff performances, mentality and leadership, effectiveness and portability of his scoring, the balance in his offensive game, impact on the rest of his teammates, inconsistency of his defense over the years, and on and on. And I don't think Wilt fans on this board or other boards get it when they try to argue exclusively through boxscore stats, everyone is aware of his numbers, but where is the impact you expect? What about all his flaws? Is this someone you are comfortable building a team around? People are wrong now that they decided to look at his career in depth rather than perform a very superficial analysis based on his raw stats like they were doing before?
As for FG%, you can't straight up compare 60s to modern day. You have to take into account the pace and lower shooting percentages back then. Wilt had the second highest FG% the year he averaged 50 a game. He shot 68.3 FG% for the 67 Warriors, and set a FG% record his last season on the Lakers that still stands to this day.
Also, Wilt shot considerably better than his center opponent in those 6 finals, including Russell.
Wilt's 62 Warriors led the league in scoring, and were second in SRS, so his putting up 50 points a game didn't seem to hurt them offensively.
I'm going to guess it helped. A lot.
Wilt's teams were almost always among the leaders in PPG and FG%'s. I get a kick out of those that use ORtgs as some kind of offensive stat...especially in terms of TEAM impact.
And while there was no question that he was generally a poor FT shooter, his TEAMs were either leading the league, or among the league leaders in FTs MADE in nearly every season (and post-season.) Again, his IMPACT at the FT line went well beyond his own shooting.