If they cared about performance they’d simply weight it more in search rankings. I find AMP pages have worse user experience because they require 100KB of JavaScript to load and complete running before you see anything, which breaks with a couple decades of best-practice, including what other Google teams advise. I regularly see AMP load slowly or break because they didn’t follow those good practices whereas sites with good engineering practice load more reliably.

It also breaks URLs – instead of the real URL, you get a google.com link which doesn’t have a good desktop experience.