But most commonly Cloudflare just blocks access to what should have been a static version of the website in the first place.
You make it sounds like it's actually very expensive to generate every single page. If so, you're doing the caching wrong. If not, then you don't really gain anything by blocking access to a few users to a static version of your website.
Source: I run a website with 400k pages; out of a single machine that I pay 30 EUR/mo for. It's kind of annoying when random Tor clients spam the hell out of my access_log. But is it worth blocking them to clean up my access_log? Not really.
I have a single server on another continent, yet my pages load several times faster than any of these Cloudflare-powered websites served from another part of town.
Let's Encrypt itself is an artificial construct that your homepage would hardly benefit from, and where Cloudflare reaps the most benefits from by having it be a selling point that noone outside of commercial entities ought to need in the first place.