I wont say exactly but they do ask for KYC. You just dont give it to them. The way this works is avoiding contracts. KYC enforcenemt is not there when you dont owe they money monthly. Pay as you go.
Discussion
If you don't pay in cash, it's KYC.
Also, they either know your home address (since they need to provide fiber/cable access to a specific geographical point) or they know your location if you just use a 4G sim card.
My point is, if feds wanted to go after the person behind your IP, they could easily do it, even if you don't KYC directly.
Harder to do it with a VPN in a different jurisdiction, not that it's impossible.