I did some page speed comparison tests with Webpagetest, GTMetrix, Page Speed Insights and FastOrSlow tools for my Wordpress blog https://community.centminmod.com/threads/cloudflare-wordpres... using Cloudflare Automatic Platform Optimizations versus without APO (with my own custom Cloudflare Worker cache + Origin PHP-FPM fastcgi_cache cache setup). Results are very close so you get a lot of bang for your buck with CF APO 1 click toggle button if you're not well versed in page speed optimisations.
However, CF APO seems to have a few teething issues to sort out
For US$5/month CF APO, has a lot of value if you don't want to go down the rabbit hole for page speed optimisations and rolling out your own Cloudflare Worker cache configuration.