If you want stripped down, grittier Chan films, he has done a few others. In his prime, he did Crime Story, which is a personal fave of mine. Still has all the action, but drops the comedy and goofiness and goody-two-shoes morality. Shinjuku Incident isn't as good, but it's even more grounded, more just straight gang violence. The last Police Story movie he did ("Lockdown") as also pretty much just a straight, gritty drama. And then of course many of his earliest kung fu films don't really have comedy and are just about straight-up revenge. New Fist of Fury is worth checking out.
I appreciated The Foreigner, too, but I think I found the way character motivations unfurled to be relatively unconventional. I think the film would've been more successful if it just followed a typical Liam Neeson arc!