He's a very good actor for a martial artist, see any of his more serious movies and it's obvious. When he's speaking in English though, his speech is poor, so he compensates for it with humor.
And he's had plenty of hits. Now that he's getting older, he's trying to focus on creating an enjoyable atmosphere in place of his amazing martial arts. The guys 45+, cut him some slack.
See a movie like Accidental Spy. He's a very good actor within his genre. Also the most gifted on-screen martial artist of his time. Sonny Chuba defies logic considering he's so big (or am I thinking of someone else), but Chan is far more adept and has done things that no other Martial Artist will even attempt.
Bruce Lee was a highly proficient Martial Artist, but his movies weren't as good and he was never the same physically after his injury. Yes I think Bruce was probably the most proficient on screen martial artist of his time before his injury. But his (trajically) short career has been eclipsed by the other Martial Artists on the list.
And Chan is also a Singer, and a danmed good one at that. That has nothing to do with Martial Arts, but man he's sings a good song.