Yea I can’t explain it either, according to his fans he’s been out of his prime since before the mcgregor fight, and the reason he started to lose is fight mileage, but also he went on a title run beating 5 top 10 opponents at bantamweight (moraes was a robbery). Funny how mileage makes you lose to champions and number 1 contenders but not anyone else
Aldo was in a motorcycle accident several years ago that has been giving him back and neck problems ever since. Not to mention he has been through some wars over a 20yr career. Aldo vs Mendes II is one of my favorite fights of all time.
That said, what he is doing now is impressive without question. At lighter weight classes, you don't see many guys in their early 30's consistently winning because speed and timing are usually the first things you lose as you get older. With heavier weight classes, speed doesn't matter so much and power doesn't fall off nearly as quickly as speed, so that's why classes like heavyweight will typically have a bunch of old guys who are still competitive because they still have power.
In addition to that, the lighter weight classes have a much deeper talent pool, because there aren't a lot of choices/sports for little guys to go to. Heavier weight classes (I'd say welterweight and up) have bigger guys and the ones who are top athletes usually gravitate towards more lucrative traditional sports, so heavier weight classes typically have very shallow talent pools, whereas smaller guys in lightweight and under will attract more top athletes, because no matter how athletic they might be, a 5'5" 145lb guy is not going to make it in pro football, baseball, soccer, or basketball. Fighting is really a smaller guys' only option, making the little guys highly highly competitive and deep with talent.
It was the same with Aldo. People said that back in the day he wanted to be and could have been a pro soccer player, however he was too small to compete with the pros, so he stuck with fighting.