I'm late to the "goodbye AMP" party, but Ethan's has been the best take I've read so far (no surprise there). In brief: it's good that AMP is on the way out, but we're stuck with it for some time, and the new Core Web Vitals still have some issues:

I’ll say again: deprioritizing AMP in favor of Core Web Vitals is a very good thing. But it’s worth noting that Google’s taken its proprietary document format, and swapped it out for a proprietary set of performance statistics that has even less external oversight.