The main issue is that not every game is important, which is why players take games off. NFL doesn’t have this problem because there are only 17 games and you have to win as many as possible to make the playoffs, so rarely is a team in position to let their best players sit out a couple times. And if they are, they either have one of the best or worst records in the league and it typically only happens last week or two of the season (aka minimal impact).

IMO if NBA can’t/won’t reduce the number of games, then they should use a format similar to Latin American soccer leagues. Have two parts of the season (Apertura and Clausura) that each have their own champion and then those champions play for the title at the very end. This would make all the games more important because instead of an 82 game single season there would be two 41 game mini-seasons (or realistically less than that to make room for extra playoff games) which would mean sitting out a couple games could actually be the different between making the playoffs or not, which is typically not the case now with so many games on the schedule, and is why they do it so often.

This split format would also kind of curve tanking because they could set it up so that it only looks at the worst record out of the two for the lottery or something so a team could potentially secure a lottery pick in the Apertura and then actually try to win in the Clausura, as opposed to simply trying to be terrible the entire year for the same outcome, which is what they do now.