Hard to say one way or the other because he's really good at leveraging his humor for dramatic purposes. He's been killing it in Righteous Gemstones, for example.
Doesn't matter imo, you'll note actors that are good at comedy are typically fantastic actors in general: Robin Williams, John Lithgow, John Goodman, Bill Murray etc.
I remember it being weird when he showed up on The West Wing as a republican who temporarily became president because he was like Dan Connor and Fred Flinstone at the time, but he worked in that role too.
Both. One of the most dynamic actors out there. He can flip from comedic to terrifying in a few seconds. His role in O Brother Where Art Thou comes to mind.
I mean back during Roseanne.. He hit the loveable father, dramatic and even scary throughout that show.
The episode where he pushes David against the door still makes me go holy shit. Then you see the blooper where he pushes him too hard and John was like omg are you okay?
If Heavy Rain actually became a live action movie especially back in the day, he would of been great as Scott. I love John's work, especially when he played Fred Flintstone!
For some reason I remember him the most from Barton Fink. I knew nothing about the movie when I watched it and everything about it really surprised me, mostly because of his performance.