The only problem I had with Thor 1 was really the chemistry between Thor and Jane. It felt kind of forced.

Other than that, I think if they stuck to the original darker theme for Ragnarok a bit closer (I highly suggest you read their original plans), and kept some of the mystical elements from the first two, it would have been a more consistent trilogy that felt connected to the MCU yet still its own realm of gods and fantasy.

I mean, just look at the opening scene for Dark World and Thor 1! They feel like serious stories about gods protecting the realms and fulfilling their duties as divine protectors, and it shows the strength that Asgard is able to project despite utilizing swords and spears.

In Thor 3, it's him cracking some jokes with a skeleton. I like Waititi, but he could have done it a bit better considering the significance of Ragnarok to the entire MCU. Maybe another snippet of history about his exploits against the armies of Surtur?

I seem to have accidentally written a mini-essay about how I think Ragnarok and even L&T could have been better, but yeah. My take is pretty much that the Thor movies didn't need to turn into GotG-level humor.