How many buttons do you want on a window frame then? The typical 4 buttons already take a lot of space in the title bar. Not everything that seems like a good idea at first glance is actually good design.
I've fucking had it with you people and your "design"
As many buttons as he thinks he needs, and as a compromise they can be disabled by default and enabled through settings. Instead your ilk will probably remove even those remaining buttons and replace them with some obscure movement command
I don't know man, everybody is fine with putting tabs, and searchbars, and a bunch of other shit in the titlebar, but god forbid we put one button that's actually incredibly useful.