The interesting thing with changes is that everyone can get upset about different ones.
But in this case I can agree with you, at the same time as I have my own pet peeves, even though I have long given up to keep
that kind of control.

I have, of course, plenty of different folders in the Bookmark menu; the main menu, and perhaps a couple of the folders have to be scrolled at rare times.
Speaking of changes, and off topic ones [mea culpa]; the other day Twitter did some UI changes, more space as you mentioned about Fx, but also colour changes ... The standard theme is and has been blue, no surprise there; however, in for example, the list of accounts who follows your account there used to be a blue button if you follow their account, and white button if you didn't. Now, standard theme is still blue, but in the list they turned colours upside down; white if you follow, and black(!) if you don't. The result: some people thought Twitter had suddenly helped them unfollow accounts (that followed them), and started clicking on the white buttons, with the result that they unfollowed ...
John Gray wrote: ↑12 Aug 2021, 07:15
Why can't they leave well alone?
I think we have to endure this period of change for the sake of change, it can't last for ever; or we have a new generation that sees it as normal.
As for Fx config tweaks, I have some (other), the trend seems to be that they are removed after some time.
Byelingual When you speak two languages but start losing vocabulary in both of them.