There's no CF magic here. If you're improving from 0.4s to 8.9s that means you're not doing basic caching on your side and you could achieve this in your local nginx/whatever as well. The 0.3s saving on first paint is nice, but could be achieved with putting your assets in any kind of distributed provider, not just CF.

I never said the contrary, but there's a lot of "basic" things you need to setup on your own and that CloudFlare (or any equivalent) does out of the box: caching, SSL certificate, basic analytics, filtering bots, etc.

Add all this together and you have an extremely not basic setup at all anymore.