I feel like I exist in this weird space where I agree that the movie constantly undercuts its drama, but that this is also my favorite Thor and, in my opinion, the best Thor we could possibly get in this version of the MCU. He just fits in better than a Shakespearean serious Thor. I LOVE Coipel Thor reminding Tony what it means to be a god and not just a man in a metal suit. But that Thor feels like it's actually more of a tonal shift for the MCU than this Thor.
I also feel like goofy Thor is more in line with how gods are portrayed in mythology. The best explanation I've ever seen is that when we (humans in general) create stories of human-like gods, we suppose of them that they would be like humans, but MORE. And that's more everything. If you can be strong - they can be way stronger. If you can be somber - they can be so melancholic that the entire world darkens. If you can be goofy - they can be absolutely ridiculous. And if you can change moods fairly quickly - they can change moods between breaths. I think this Thor holds to that quite well, even if it's not everyone's preferred way to portray the character.
In the original mythology, Thor dresses up as a woman and marries a giant to get his hammer back. That problem -began- because the giant wanted to force himself on Freyja. Their (Loki and Thor) first idea was to just .. let him marry her. Her response to this idea was to almost literally go super saiyan at them. So instead they dress Thor up like a woman, ride back to the giant in Thor's goat-chariot, and have a wedding in which Thor is obviously Thor because he eats and drinks enough to kill 20 men and the giant is terrified to even look in Thor's eyes. But it's okay because they convince him that the eyes of the bride are only terrifying because, you know, she's a woman and women are scary when they're tired.
Then they bring out Thor's hammer and he kills people with it.
Dizzying tonal shift is a Norse tradition.
Also, taken completely out of context, Thor using his real lightning powers for the first time and coming down onto the bridge to Led Zeppelin? Peak cinema.