TBH I think the humour is almost 1:1 consistent between to the two movies. If you watch Ragnarok again, all of the comedic pacing of the film, right up until before Hela shows up, it kinda has the same feel as the first half of L&T. It's a little unfocused, very silly, not ever really settling into anything dramatic and juicy. The difference is, once Hela destroys Thor's hammer, we get a great tonal change and Thor is given a really clear and solid goal, that the audience gets behind. From there on, the humour is mostly fine because because it's supporting a clear narrative goal.
So I think the biggest divergence is the narrative stakes in Ragnarok are much higher, much earlier on. For Love and Thunder, I think the absolute biggest stakes are Jane's cancer. It hits hard the moment you realise her situation, and then it hits even harder by the 2nd half when Thor learns of it. The problem is, in the middle there, because Jane is keeping it a secret, we're not really doing anything with those stakes. The other narrative stakes are Gorr using his wish to kill all gods, but yeah, we learn that SO late and have no attachment to the other gods, it doesn't quite feel as important. Compared to Ragnarok, which was all about saving Asgard, Thor learning his true power, writing wrongs etc.
That said, I still really liked what Taika tried to do with this film. I don't think it's totally fair to compare it to Ragnarok completely because I think both were exploring very different narrative ideas. I kind of thing the whole point of Love and Thunder WAS to be very light and silly... Because what's hidden underneath that is the very real tragedy of Jane. The film itself is kind of a mirror of how both Thor and Jane are choosing to hide their pain. Thor is masking his clear depression with "Classic Thor Adventures" and Jane is doing the same. By the end of the film, I feel like I'd picked up exactly what Taika was putting down.
But yeah, I think people tearing apart the jokes are under the impression that the jokes in love and Thunder are worse than Ragnarok but I think it's just the comedy pacing. There was just too much back to back silliness I think that could've been beefed up with some more drama/narrative in between it. I think silliness feeding off of drama is the sweet spot, but silliness feeding off of silliness gets tiring.
For me, the #1 thing I would've changed would be to lose the Guardians stuff (or at least cut in half), and have Thor and Jane connect sooner. Have Thor discover about the cancer sooner and make the film way more about the two of them. I do love Valkyrie but she didn't have much to do and I think the story would've been stronger if they'd just committed to her and Korg having smaller roles.
A Thor and Jane solo road trip through other worlds together could've been really sweet and I think had a bit more focus.