Conor doesn't know how to throw punches properly, so not very well. The second he gasses a little, his punches lose all their power, because Conor doesn't understand how to use his hips and feet to generate power. He throws most of his punches with this support foot in the air and with only his arm. Also, he's somehow managed to never learn a proper jab (and his roundhouse kicks look horrible too).
It's absurd a professional fighter has flaws like this so far into his career, and the only possible explanation is that Conor is surrounded by yes-men that don't have the nerve to correct his form until it's correct -- instead they just praise him.