McGregor definitely did not build himself up. Once the UFC saw he was marketable(He's a character), they threw the weight of UFC marketing behind him, and gave him the path of absolute least resistance to two title shots. We actually talked about this in this thread awhile ago. I ran down his path to Aldo, and if memory serves, he fought 2 guys who were top 10 in the division at the time he fought them on his run to Aldo, and one of them took the fight on 7 days notice or something, and he was not in peak condition. He avoided 7 other opponents who were top 10 during that run.
I'd argue that had the UFC not made McGregor a darling, it's debatable he would have ever gotten to Aldo before he got beaten. McGregor got to skip he queue, and avoid the best wrestlers in the division, or fight one of them, who was not in camp and was not in proper condition. McGregor did beat who they put in front of him, until 155 pound journeyman Nate Diaz stole his soul when they both went up to 170, so you can't take the fact he did beat who he had to beat away from him. However, he quite literally had the luck of the Irish with him by avoiding the murderers row of dudes at 145 and 155.
In Eddie Alvarez, McGregor imo got the ideal match. Sort of like GSP and Bisping. GSP beats Bisping, he probably loses to almost everyone else in the top 5 of 185, he might beat Rockhold cause Rockhold is has a fight IQ that would embarrass a rock. McGregor got Alvarez, who just isn't very good, but managed to get a win over Dos Anjos.
Now McGregor is inactive, and he is creeping up on the magical age where fighters who predicate their skillset on speed and reflexes (McGregor is a reflex based counter puncher) start to drop off because their body just can't keep up with their reflexes. We might actually get robbed of seeing how good McGregor actually is/was because he hasn't tested himself against enough of the greats of his era.
His best wins right now are Holloway, who was a kid when he beat him, and Aldo, which could have been a fecking fluke. Although it's quite clear now that Aldo has been bitten by father time, he's slower, and he's the right age for that slow down. McGregor is now looking down the barrel of father time in the next couple years too. So it will be interesting to see if he sticks to his guns and doesn't fight, or if he tries to get some legacy wins before some 25 year old in his physical prime turns him into a scalp.