NBA has a bigger court, deeper line, three-second rule, and an 82-game regular season with defense tightening up enormously in the playoffs, but ask a Coli hot take and they'll say the NBA "doesn't play defense" and is "soft".
Yet an NBA squad giving the most minutes to KD, Carmelo, and Kyrie held the best teams in the world to 66, 72, and 78 in their last three Olympic games.
Alexey Shved is leading the euroleague in scoring at 25.2 ppg

and was mvp last year

ALL the good talent in the world is in the NBA. Any mobile 7-footer, any athletic fool who can jump out of the gym and has actual skill, they'll be in the NBA. The NBA has more global talent now than ever before and everyone else is fighting for scraps.
In Europe you see real defensive schemes consistently. In the NBA it's just in the playoffs. Which is why guys like Kobe and LeBron say real basketball is the playoffs.
Yep, those Euroleague guys play what, 30 games? With like a 4-game playoff?
When you have to play 82 games and a 20+ game playoff you're not going to go all-out in every damn game. Defensive effort on a play-by-play basis in the regular season actually increased a lot in the 2000s, and the result has been an unprecedented number of injuries cause human bodies can't take that kind of effort for 80-100 games without stuff breaking down. But when the playoffs roll around, guys like Harden (and soon to see Luca) have a much harder time getting buckets than they did against regular-season D.