Most big services will just take the junk traffic. They're never going to block whole cloud providers.

Blocking cloud providers is strictly for us dirty self hosters who are sick of our logs becoming unreadable and our visitor metrics useless from all this malicious traffic.

Does the money add up for that to be a deterrent? Are those using them for general VPN access paying enough that they'd care much, and if so is that enough compared to what they'd lose by kicking off the users abusing external sites (they can't all be using just free plans, and anyway tests to kick them could have enough false positives to lose them good paying customers as well as bad users). In any case is the amount of traffic enough for them to care to spend the effort tracking it to identify the bad users?

If advertising and tracking was less egregious, I wouldn't feel the need to use an ad blocker. But, here we are.