Middleweights still can have just as an exciting fight as heavyweights.. so can welterweights. look at this bout between hearns and hagler
https://youtu.be/9VI-M9Yw-28?t=121
Look at hearns trapped in the corner.. instead of hugging to force a judge to intervene, he ducks, corners and counters his opponent.
I am more than confident mayweather could do the above as well, but he plays it way too safe, thus making his fights boring af.
Yes he will be walking away with his many millions but he isn't doing justice to the sport at all.