It's interesting to compare the user responses to updates by Facebook and Twitter respectively.
Facebook's UI has changed significantly over the last 15 or so years. Features have appeared and disappeared, boxes have been arranged and rearranged. But there's rarely a big fuss beyond it getting a little slower each time (roughly commensurate with consumer hardware speedup, in fact). People don't really notice and they don't really care. People originally balked at the reactions feature, calling it gauche and unnecessary - but now people use it as part of the language of the platform without a second thought.
Compare with Twitter. Every UI "overhaul" they've ever done has been received in a hugely negative way. The only change which has been remotely successful was the 140/280 switch.
The difference is threefold:
First, Twitter's UI changes have been big. They skip over incremental changes and go straight for gigantic overhauls. This requires people re-learn the language of the site completely every couple of years.
Second, these changes have invariably been coupled with user-hostile design decisions. The obvious one this time round is the automatic switching to "AI sorted timeline" on every visit. No wonder people have an almost pavlovian response to the design changes.
And thirdly, while Facebook's changes are usually to accommodate changing usage patterns, new features, or new hardware, Twitter's updates are very transparently pointless. They offer zero improvement to the user experience for any sector of the market. Every change causes people to question why they use the site in the first place.
Gosh I didn't expect this to be such a long rant. Turns out I have a lot to say about the terrible design decisions made over in Twitter land. The conclusion is this: people don't hate change. They hate change which makes their lives worse than the status quo would have done. It's not complicated.