This seems like the same problem with have with RAM requirements, we have more resolution and RAM than we used to have in the past so developers and designers waste more of it because they don't need to be as careful as they used to.
But using much ram is still bad. Using much whitespace is viewed as a staple of modern design. I don't like it either, I have enough empty space on my wall. I buy my screen to display information.
The proton enable thing will go away in the next version. The compact mode will probably keep working a while longer but as they recovered the UI option for it, the writing is on the wall...
Aside from various coats of paint, the Chrome tab UI is still the same. Which I'm thankful for. Firefox has gone through a few redesigns lately; Australis, Photon, and Proton (latest)