Exactly. They're renting infrastructure on well-known clouds, not cycling through consumer IPs like yesterday's botnets. Block all web traffic from well-known cloud IPs, and you can keep 99% of the LLM bots away. Alibaba seems to be the most common source of bot traffic on my infrastructure lately, and I also see Huawei Cloud from time to time. Not much AWS, probably because of their high IPv4 pricing.

You can allow API access from cloud IPs, as long as you don't do anything expensive before you've authenticated the client.