Re: More difficult to do: three-peating or making the finals 10 straight?
Does the person making the Final ever win? Does the person 3peating make the Finals any other times?
It's hard to say looking at them without context. If you make 10 straight finals but never win the championship, logic would dictate that the conference you dominate was weak. If you 3peat then never make the Finals again, then your team had a short window to win. Not a fluke, no one luck's into that level of success, but it wasn't sustainable for a long time for whatever reason. Neither of these are bad
All things equal I'd say 10 straight Finals is more difficult only because sustaining success over a decade is extremely tough. Winning 3 straight rings is greater in the short view. Basically it's the difference between peak/longevity arguments.
Though if it's which I'd rather do and which is greater legacy wise, I'd say the 3 peat.