It’s effective against teenagers maybe. Not so much against Amazon, Meta or wherever botnet/crawler is coming out of China these days from up-and-coming AI companies.
If they can't keep their ranges clean to a reasonable degree, their customers will need to move if they want to access your part of the internet. New sign-ups will always be hard, so some amount of abuse is expected, but if it's the same abuse traffic for weeks after you've notified them, well, it stops being your problem at some point