The purpose of AMP, when it came out, was to serve content ultra fast. It was meant for news sites. But more and more sites jumped on the amp bandwagon as a way to serve content really really fast to mobile users.
Flash forward a couple years and now site speed in general is more important than ever, which then makes AMP less valuable.
In other words, if your site is fast and responsive, then AMP isn’t necessary.
that being said, yes I do think core web vitals will apply to amp pages just like regular pages, however by default amp pages should be faster because they use less code to render page, so there shouldn’t be issues. And if you have speed issues with your AMP pages then you have much bigger issues to resolve.