Google is releasing the Page Experience Update and part of that is the core web vitals will become a ranking factor and you would want your pages to be fast. If you make use of AMP, then google will use your AMP page for measuring those factors. Google’s John Mueller states that it is not considered as cheating to use AMP.

Here Are The Tweets:

Hey @googlewmc @JohnMu @dannysullivan with the new #webvitals "ranking factor" and news on removing the @AMPhtml requirement from Top Stories – which version will be considered for evaluation? the URL or the cached? As our cached AMP has much better scores than our valid AMP? pic.twitter.com/AKti6ExKSb

— Dan Smullen (@dansmull) June 22, 2020

John States That Google Measures What The Users See: 

The general approach is to measure what users see in practice.

— ? John ? (@JohnMu) June 23, 2020

Recommendation: Google Search And Discover Algorithm Ranking Update

Is This Cheating? John Responded NO

You can make slow AMP pages, you can make fast legacy pages. Using a framework that's designed to be fast isn't cheating when it comes to speed — if it's the right tool for the job, then it's a potentially logical approach. Luckily, there are lots of ways to make fast sites.

— ? John ? (@JohnMu) June 23, 2020

You do not have to specifically use AMP, you can make use of anything you want to make your pages fast. But Google usually considers AMP as super-fast, reason being as it is designed to be fast. You can also make the AMP pages slow and then Google will also consider those pages as slow.