He's obviously a very good fighter, but I've never understood the hype and why people seem to think he had anything for Khabib. The guy was controlled on the ground by Kevin Lee, and was fortunate that Lee gassed and allowed him to get the triangle. Most of Tony's best wins were not dominant performances either. Even when he beat Pettis, he was dropped in that fight and was losing until he wasn't. His main strength has always been his toughness/ability to recover, accompanied by his amazing cardio. Sure, his BJJ is great, but he has no takedown defence, and we've now seen at least 3 guys control him with ease from the top, all of whom have lesser top-control skill than Khabib (Lee, Charles, Dariush).
I like Tony, and I'd have liked to see him win his last couple of fights, but I'm not convinced he ever had anything for Khabib, and I'd expect even Poirier and Conor to beat him as well.