I had it for a while and it did help speed up my site, but it removed a lot more basic javascript that actually helped the site, so after a year I was sick of it and just removed AMP. Instead, I focussed on improving my site in general. By removing some plugins, keeping the styling consistent, and not use too many blocks from WPBackery, I greatly improved the field data in Google Speedtest, now I’m all green. AMP is useless.