Is Cloudflare blocking crawling?

Short answer: yes.

would very much appreciate a long answer, or a link to one would do

Just a lot of anti bot logic

How do you get around the captcha or whatever they call their "click to prove you're a human" thing they do on half the web now? Oh you have to report to Cloudflare what you intend to do, when, how, etc, and if they don't like it you're SOL. This is just a fact about the Internet, you can't debate or refute it so describe to me how they're not blocking crawling for their partners.

I've long suspected Cloudflare itself commissions DDOS attacks just to sell their own services and that they attack rivals too. Look at one of the live maps of cyber-attacks some time, you'll see a lot originate and are destined inside the US, and that they mainly come from cloud providers. Then just imagine how cute you'd feel about yourself if you figured out how to use the cloud to burn everybody who didn't pay you protection money or enter into your free tier where you merely own the TLS certs. I think they got a bit too cute just like we've seen before with the dragon infitity logo signature the NSA uses.

https://www.2captcha.com/ is a popular (paid) captcha solving service, but there are many others out there.