Agree with nearly every word. Wished I could've been one of the people who was cheering and so emotionally engaged... but I wasn't, for basically all the reasons you mentioned here.
Also, the Garfield movies are really bad. Garfield's the MVP of this movie, he's terrific here-- but the nostalgia I see developing for those movies is bizarre. Like, people cheered in my theater when Jamie Foxx appeared as Electro! He was very bad in a very bad movie! Why are we happy about this? Genuinely made me curious if audiences would cheer if John Travolta rolled into a future MCU movie as The Punisher from another multiverse-- or if Jennifer Garner popped up as Electra, lol. Like, are we experiencing genuine nostalgia for things we enjoy... or are we just feeling pleased whenever we see Marvel (or Star Wars, or any major cinematic universe) go back to any familiar well?
But I'm happy so many people loved it. It's always fun being part of a theatrical experience like that. Way less fun feeling left out, lol.