We already had a universal copy/paste in Linux: Mark with left mouse button, paste with middle button. This used to work for just about everything. However, lately browsers started to ignore this when I mark the URL and try to paste it elsewhere, for example. Instead I get the old clipboard. I have to use the left button multiple times - and it works. Falling back to Windows-style copy/paste, either with keys or pull-down menus with "copy" and later "paste" is, to me, a huge, inefficient step backwards and it's frustrating me every day.

Addon: For purely non-mouse work, think serial terminal, I for one want Emacs bindings. Though that's typically configurable for the shell anyway, so everyone can choose what they prefer.

I think the multiple clipboards are great. My only regret is that there aren't more of them. Three would be excellent. But having multiple is very good, both for the pattern of "paste one thing over and over again, interspersed with copying and pasting other things" and for the pattern of "copy 1; copy 2; paste 1; paste 2" or "copy1; copy2; paste 2; paste 1" with only a single application switch.

When firefox screwed up the address bar so that the left-click/middle-click didn't work right was easily the worst step down in computing for me in modern history. Initially you could recover the non-chrome like behavior with a preference but they eventually broke that too.

> We already had a universal copy/paste in Linux: Mark with left mouse button, paste with middle button.

We still have it, at least for text. I just copied the little quote above with left mouse highlight, middle mouse paste while writing this comment in Firefox in Gnome 48 with Wayland. I use it a lot on the terminal.

What doesn't appear to work anymore (at least in Wayland) is copying a selection as a bitmap into a bitmap editor, ie. paint. Only a few decades ago that used to work, I remember that.