Every popular HTTP server supports gzip compression, but you still have to turn it on and surprising number of sites don't bother.

IIS, for instance, makes you install "Dynamic" compression separately from Static compression, and it's not on by default. They also have some stupid frequency measurement, so you can end up with slow first loads until IIS decides its time to compress files. And changing it requires modifying some global config deep under system32.

Supposedly they separate all these little features out (no telnet client or tftp client!) for security. But it's really a cover-your-ass style that results in worse security for many users which just install everything trying to make stuff work. Dynamic compression being separate is a great example of that.

Given how gzip is the single most effective way of reducing BW consumption and site-loading speeds, I think we can conclude that those who don't bother don't really care about performance either way.

And in those cases HTTP 1.x vs HTTP 2.x is a moot discussion anyway.

Even if site administrator's don't care, users do.