Partially because Chan is older in those movies and is a little less physically capable.

But IMO mostly because of Hollywood's unfortunate style of directing fights and martial arts battles.

Traditional Hong Kong martial arts movies use a lot of wide and long, unbroken shots. You can really see the performers performing these physical acts of skill and beauty -- you see their entire bodies, it's almost like watching performers on a stage. Which is of course Chan's background.

In contrast, Western directors typically use a lot of fast, tight, jerky, almost seizure-inducing cuts. A closeup of a fist hitting a face. A closeup of an elbow hitting a knee. A closeup of a face showing somebody's reaction to the pain. Etc. etc etc. There's much less continuity. 98% of the scenes are probably shot by stunt/body doubles. It doesn't take a lot of talent for an actor to pull off a scene like that, at least not compared to the traditional HK style where the actors have had a lifetime of martial arts training.

Of course, those are vast generalizations. You can name plenty of counterexamples from both schools!