Regarding dedicated servers,
To my understanding, dedicated servers works like this:
Client X is playing from the moon. Their game appears laggy and their input to the server is different than what they see.
Client Y is playing right next to the server. Their ping is smaller than my brain. Their input to the server is almost perfectly synchronized.
The server says client X is in position A, but he sees himself in position B because of his lag. Client Y walks up and swings at position A, where the server says Client X is. The server registers Client X as downed.
So in that case, visual inconsistencies and invalidated hits should be the fault of the client's connection to the server, not that of any other client. VPNing and all the other things people complain about can't be the issue for ridiculous hits. If lag switches don't work anymore, neither should naturally bad internet.
Comments
You could flip the roles but the outcome would be the same.