>>212292554C'mon, man.
Spider-Man: No Way Home could have, for example, shit on The Amazing Spider-Man movies, since they weren't that beloved. But despite the producers desire to rely on nostalgia, and they did rely heavily on it, what with all those corny as fuck callbacks to all the random bits of dialogue from Sam Raimi's movies, they remained respectful to Garfield's character, and even took it to some heartfelt places. It also helps that it is a Spider-Man movie about other Spider-Men. To the point audiences actually wanted to see more out of Garfield's Spidey.
Meanwhile The Flash just added Michael Keaton because it was Michael Keaton, and they thought there were still people nostalgic for the Tim Burton's movies. Not for anything related to Burton's ideas, though, because they stripped that movie from anything really related to Batman an Batman Returns. Keaton was just there because they were priming to bring him back as an actor so they could replace Ben Affleck as their Batman. For some reason everything else, outside of Keaton, relates to the Snyder's movies, that they're trying to reboot, creating this weird convoluted scenario that won't make anyone happy.
Reminder that originally the new universe would essentially be what their version of Snyderverse was at that point, but with Keaton being revealed as having survived and becoming the mainstay Batman, and in this new timeline Keaton's new Bats isn't a killer either because that also changes since it is a no-no. Basically the execs picking and choosing shit not based on what makes sense, but what they think the audience want to see in a very stupid ways.
Then Gunn came in and said nah to the Keaton plan, and erased that shit, so the last scene with Keaton in that movie is him just dying. The Flash now just finds himself stranded in another universe, that also looks like Snyderverse but not really. And that's it. Just a mess.