Because with HTML you get static, non-flashing, intstantly rendered without load times. So smart developers actually want less Javascript, because the browser already implements most of what Javascript does, why reinvent the wheel?

Why would I write React components myself when I the Javascript isn't really that complicated?

It is bizarre that ONLY HTMX gets these weird "DONT USE THAT ITS NOT POPULAR ENOUGH" criticisms.

XML, XLST get these criticisms except for the XQuery and XPath components because HTML fanatics need that to make their hybrid HTML/JS garbage apps work.

But really the ultimate goal for any good website engineer should be to offload as much logic and processing to the browser, not rewrite everything in JS just because you can.