ISPs are supposed to disconnect abusive customers. The correct thing to do is probably contact the ISP. Don't complain about scraping, complain about the DDOS (which is the actual problem and I'm increasingly beginning to believe the intent.)

Great! How do I get, say, Google's ISP to disconnect them?

Every ISP has an abuse email contact you can look up.

Sure, let me just contact that one ISP located in Russia or India, I am sure they will care a lot about my self-hosted blog

Hence the need for Cloudflare?

I am not comfortable with a private company being the only solution, especially when they have a history of deplatforming sites.

Except that's exactly what you should do. And if they refuse to cooperate you contact the network operators between them and yourself.

Imagine if Chinese or Russian criminal gangs started sending mail bombs to the US/EU and our solution would be to require all senders, including domestic ones, to prove their identity in order to have their parcels delivered. Completely absurd, but somehow with the Internet everyone jumps to that instead of more reasonable solutions.

The internet is not a mirror of the real world.