Hmmm...Are you being sarcastic? It's hard to tell.
Either way, Fishron is much faster than any other boss and also hits MUCH harder. I can beat the Twins in seconds without moving, with top-tier equipment. I can't dream to do the same with Duke Fishron.
Did you try the UP key in combination with the RIGHT key?
No?
If you stop focusing on gear requirements and start dodging bosses, they will become much easier. ESPECIALLY if they are Fishron, a boss who keep charging into where you were 5 seconds ago.