I want to point out that Twitter was able to block you by iP Address and association. Twitter tracks you. So, they know if you have multiple accounts, because usually they were all using the same app. So, they had two options. People, who circumvented a block would find all tbeir accounts suspended. They then would have to either a phone number to unlock them or file an appeal.
Twitter was able to connect account even on 3rd party apps.
The second issue is people who usually get blocked for harassing have built up an identity. So, harrassing from a new account is not the same. This is why some sued public officials for being blocked. Everyday people were able to identify alternative accounts of bad actors.
So, blocking is more effective than you think. They have tracking withong the apps. Your IP address and an algorithm that I don’t know too much about.
I would think people would guess some of what I mentioned since Twitter broadcasts what service and/or device you are Tweeting from.