The game is so much faster in terms of pace, and in terms of players being bigger and faster. That's the real reason for injury caution.

I think the difference is that teams are more cautious because they don't want a season disrupted by a major injury. Zion the other day said that the Pelicans were the limiting factor in his sitting back-to-backs. Players frequently come back on minutes restrictions (Kawhi previously, Exum currently).