As soon as you have a few of their IPs, look them up on ipinfo.io/1.2.3.4 and you'll find they probably belong to a handful of hosting firms. You can get each firm's entire IP list on that page and add all of those CIDRs to your block list. Saves you needing to make 30K web requests.

In most countries in the western world, there are 3-4 major ISPs and this is where 99% of your legit traffic comes from. Regular people don't browse the web proxying via hosting centres as Cloudflare will treat them with suspicion on all the websites they protect.