A subset wouldn't require you to load js to use built-in features like forms. A subset would just remove features or elements, which would make the whole load a js lib to make it work superfluous.

AMP is not a subset of HTML. It's a superset of a (badly defined) subset of HTML.

A "subset of HTML" that by specification is required to load Javascript from a central CDN, and by specification will let you wait multiple seconds before it shows anything if that JS doesn't load, even if perfectly usable content is loaded already.

AMP is an unethical scheme by Google to appify and control of the Web. There are many articles about it.

Here are some other pages:

https://duckduckgo.com/?q=site%3Anews.ycombinator.com+amp&t=...