Sorry, but the <template> tag doesn't actually do "templating in HTML"
...but it should. It's shocking to me that we've had the modern paradigm of client-side-rendering frameworks for over a decade now, without so much as an RFC for any kind of native support.
For the sake of render performance, bundle size, removing a need for transpilation, compatibility across frameworks. There are a million reasons this should be happening in the browser at this point. I'm sure it's a complicated standard to come up with (for one: HTML-based vs JS-based rendering), but why does it feel like nobody's even trying?
There's no lack of syntactical templating mechanisms when HTML is hosted within a SGML markup processing context (ie how HTML started life), and no need to add templating at the HTML markup vocabulary level either:
For server-side rendering, SGML (and also some other template "engines") provide HTML-aware, type-checked, parametric macro expansion. Actually, SGML templating works transparently on the client side and the server side.
Within the browser OTOH, there's already JavaScript, making every dynamic feature added to HTML inessential for better or worse, like it has for over 25 years now. That's just how it was decided a long time ago, and adding half-assed features to HTML like the template element (which requires JavaScript, in turn, thus doesn't add any essential capability) all the time is exactly the thing we shouldn't be doing when the damn "web stack" is already bloated as fuck.
...but it should. It's shocking to me that we've had the modern paradigm of client-side-rendering frameworks for over a decade now, without so much as an RFC for any kind of native support.
For the sake of render performance, bundle size, removing a need for transpilation, compatibility across frameworks. There are a million reasons this should be happening in the browser at this point. I'm sure it's a complicated standard to come up with (for one: HTML-based vs JS-based rendering), but why does it feel like nobody's even trying?