Long 7 game playoffs back to back to back to back do not matter? Ask Durant and Thompson.
Others missed games and / or played hurt.
Same with NHL, several were playing dinged (eg. O'Reilly, cracked ribs middle of the NHL playoffs, played thru it and was back to 100% for the Bruins series).
I wish I had a dollar for every time I heard a coach or announcer say the playoffs are a "game of attrition" as they explain injury woes in the NHL and NBA.
Check the weights of players in the 80's and 90's, and if you see an "ESPN Classic" NBA game, with, say, the Magic Johnson Lakers vs the Larry Bird Celts, it is almost funny, they all look skinny as hell.
The difference is, these days, going against HGH supplemented weight lifting mutants is completely different, it takes its toll, it is very different. Hockey, too, the players are enormous now, weight training backfires when it changes your body and makes it more vulnerable to injury as you push it to the limit.
We are not seeing the best of the games as they should be, too many are dinged or knocked out of the game.