McGregor is an amazing mixed martial artist. And yes, boxing is a part of mixed martial arts. But he is up against someone with 49 consecutive victories.
And even if you think he’s showing amazing boxing in MMA - that doesn’t mean much. MMA boxing is completely different from boxing. Different gloves, different stances, different concerns (does this put me in a good position to kick/defend a take down?) and different rules (MMA has spinning backfists, boxers don’t need to worry about the clinch).
McGregor is going to lose, and badly. I don’t see how a former amateur boxer making his professional debut after a long stint at MMA can do anything against the greatest professional boxer alive.