> Author’s argument is those hardware improvements could have been had for free with X11 upgrades.

I do NOT miss having tearing all the time with X11. There were always kludgy workarounds. Even if you stopped and said ok, lets not run nvidia, let's do intel they have great FOSS driver support, we look back at X11 2D acceleration history. EXA, SNA, UMA, XAA? Oh right all replaced with GLAMOR, OK run modesetting driver, right need a compositor on top of our window manager still because we don't vsync without it.

Do you have monitors with a different refresh rate? Do you have muxes with different cards driving different outputs? All this stuff X11 sucks at. Ok the turd has been polished well now after decades, it doesn't need to run as root/suid anymore, doesn't listen for connections on your network, but the security model still sucks compared to wayland, and once you mix multiple video cards all bets are off.

But yeah, clipboard works reliably, big W for X11.