where a repo is forked but the new maintainers don't change the repo's did
A DID is a public key. If you don't know the corresponding private key you won't be able to make any updates. All you'll be able to do is mirror it.
instead just get more nodes to follow them than the original
This is like saying "but I can fork Verisign's Root CA certificate and get more nodes to follow me than Verisign!". No, you don't have the private key that goes with that root certificate. So everybody will ignore you.
A DID is a public key. If you don't know the corresponding private key you won't be able to make any updates. All you'll be able to do is mirror it.
instead just get more nodes to follow them than the original
This is like saying "but I can fork Verisign's Root CA certificate and get more nodes to follow me than Verisign!". No, you don't have the private key that goes with that root certificate. So everybody will ignore you.
Cryptography is not a popularity contest.