What we need is a subset of modern web, without any bloat, especially JS frameworks.

A lot of websites can be static HTML + CSS.

A lot of websites can be static HTML + CSS.

Yeah they can, I can understand you might want to use something like php to not need to edit the footers and headers every page if you ever change them, but still.

I also like how some websites like Amazon.com refuse to add a payment platform which is more than a credit card checkout. Especially because their EU sites do have payment platforms with more options to pay. So then you have an over complicated site already with a lot of bloat and some amount of your consumers can’t even pay.

Then use a site generator like Hugo or Jekyll to stamp out new versions of your site with matching header/footer/etc.
Some of these are extreme, but what you’re talking about is the 512kb.club, just keep it small, but no limits on what you can use.
512KB Club

The 512KB Club is an exclusive list of web pages weighing less than 512 kilobytes.

512KB Club
The subset exists. What you’re referring to is an agreement or convention.
We have that, it’s called Gemini and is accessible with Lagrange

Maybe a little JS, as a treat?

It’s fun for hiding little easter eggs.