Or is funny Thor just written that way as an extension of Chris Hemsworth comic instincts?
The characterization of Thor in the comic books varies over time, as different creative teams took on the book. Though there is often some comic relief in the books, generally, he’s not particularly funny in the way he was in his more recent MCU appearances (Thor: Ragnarok and later).
I figured he was more pompous than funny in the comics and also in the first movie, sort of overwrought and melodramatic. The humour in the movies began from taking him down a peg or two, and then it evolved into what we have now.
I’ve never quite gotten a sense of Thor’s power in the MCU.
We are led to believe he is almighty and one of the most powerful beings in the MCU. But he gets his ass handed to him with some regularity. He overcomes in the end (as all superheroes tend to do) but still…
I took it as gradually increasing the power scale as in the comics. At one point, Hulk was strongest there was in the MCU, then Thor came in and managed to fight him successfully if not to a conclusion, thenHulkbuster (somewhat), Captain Marvel showed up and Thanos, both of whom could give him a good battle if not win (in Thanos’ case).
I think that Hulk is still, canonically, “strongest one there is”, but strength is not the same as power. You can still beat Hulk by outsmarting him or outmaneuvering him or the like, just not by directly matching strength vs. strength. And he doesn’t really have much in his (usual) toolkit besides strength, so his overall capability level isn’t that high (aside from those cases where Banner and Hulk coexist cooperatively, like in Endgame).
Thor still mostly relies on his (not quite Hulk but very considerable) strength (because of course, to him everything does look like a nail, after all), but he does have a few other options in his toolbox.
Chris Hemsworth is a naturally funny guy. Most of the humor that crept into the character was from ad libs and not in the script. Then when you get to Ragnarok you have a director who was a comic who encouraged improvisation. Thor’s personality as he is now formed in the MCU has more to do with Chris Hemsworth than the comic books.
Thor is usually played seriously, and the pseudo-Shakespearian language often comes off as pompous.
But every now and then . . . .
From the Frog of Thunder storyline, late 1980s.
Thank you mbh for sharing the Frog of Thunder storyline. My best bud is a huge fan of Thor and I need to find a poster of this for his christmas gift or something. Thats cool. 
I’ll have to frame it for him.
I think that’s more a case of “comics are silly” than specifically “Thor is silly”.
Fun trivia: When Loki transformed Thor into a frog, Thor acquired the ability to communicate with animals.
After he regained his normal form, he was still able to communicate with frogs (I don’t know about other animals.)
