Because 11 is perfect and free of any reasons not to use it? I think most people define "best" as the the most upsides with the fewest downsides. Something need not be perfect to be better than alternatives.
To your specific complaints, it only doesn't play HEVC ootb if you're using a crappy player that needs the Media Foundation codec. Even if you are on 11, the available MF codecs are extremely limited; only a handful exist. Subtitle support is worse. Every user is inevitably going to run into something that won't play and have to get a better player. This is not just old formats, but new ones too.
Most people watch their media on TV or non-windows tablet. Or use Apple. Or are fine with using it in their browser. Legions of people clamoring for the Store version for their PC exist only in the minds of MS product managers. A quick search indicates newer Edge versions allow 4k in the browser too.
What "game related features" am I missing? People game on LTSC all the time. Gimmicks that just get in the way? That stupid Xbox service in enabled by default on LTSC too. Very, very few games take issue with it, maybe we could compare numbers for ones that don't run on 11 at all.
Oh, Lightroom is artificially limited to 22H2? Well clearly this is representative of fucking everything and everyone and no program ever made doesn't work on 11.
Yes there's niche cases where you need a specific Windows version, but that's *not* 11 more often than it is, and doesn't determine overall best.
And like most of the people here, I may be "some nerd", but that means I get roped into tech support for family, friends, etc, that aren't, all the time. People have more complaints and problems from 11 by far than the ones who let me set up LTSC.
Finally this is a fucking tech site, so nerds are the target audience. For people who actually read my post, they're not the non techies who can't install VLC or MPC. You sound like the kind of fanboy who turns telemetry to maximum on purpose.