I think part of it is getting old. The more you live, the more movies you see, the more you recognize plots or see reboots. Sometimes asking why you'd even try? Especially for classics. Like the new Willy Wonka, new Robocop, years ago, a TV remake of the Shining. Do they honestly think they'd do better than classics? The only reason they're remaking them is for money. They think because you loved the old one dearly, you'd want to see a remake.
Though sometimes it's a hit. The movie version of It far surpassed the old TV miniseries. Though I wouldn't have considered the miniseries something awesome in the first place. Another exception, King Kong. As good as the original was, the modern effects make it so much better.
I honestly don't think it's been that long, but I'm watching the 3rd set of Spider Mans. And 3rd person playing the Hulk. 4th if you count the TV series from the 70's.
Hollywood is a bunch of hacks. How much is really new? Full of well exhausted tropes.
What really irks me is the lame superhero plots. I still watch them for the action. But looking over the past several years... Who does Superman fight in Superman 2? Other Kryptonians so he's equally matched. Or in Superman 4, another type of Superman. In the Ed Norton Hulk, he fights another hulk. Spiderman fought Venom, a kind of spider man. Ant Man fights Yellowjacket, another shrunken guy. Black Panther fights another Black Panther. Iron Man fights another guy in a super suit, then in another movie, a guy with another power cell. Doctor Who often battled The Master (another Time Lord). In the latest Star Trek Kahn movie, they battle a larger version of the enterprise.
Are the writers that F'ing lazy that the only villains they can dream up are ones that pretty much have the same super powers as the hero, but are evil?