The same folks that thought Ronda Rousey was one of the greatest fighters of all time think a boxing match between Mayweather and Conor would be competitive. Mayweather may not knock him out, because he'd rather out box and embarrass him for 12 rounds, but the fight wouldn't be close.
The UFC's business model over the past 2 years has been to manipulate the casual fan by promoting fighters like Mc Gregor and Rousey as unbeatable or all time greats and by making outlandish statements like Ronda could box with Floyd. Eventually the casual fan will get let down 1 too many times. That's why you will never see the Floyd vs Conor fight as long as Conor is under UFC contract. Floyd would love an easy pay day. There are still fights left for Floyd but he doesn't want to fight guys that stand a chance of beating him. He'd rather promote this garbage...