One of the clearest examples of this for me is having the address bar at the bottom on mobile devices. There is pretty much no disadvantage to placing it there yet whenever a browser does that, people get inevitably angry. I hope Apple sticks with it and the other iOS browsers like Brave adopt it.
Was this an optional setting? Was it suddenly turned on with the option to turn it off buried in a settings menu than normal users are scared of?
I actually didn't know iOS had this, I only know about FireFox on Android and it asked me if I wanted to opt in before thrusting it upon me. That's a good way to make major UI changes.
Edit: point proven