Jones is the same as he's always been, and even steadily made significant improvements to his game. Instead, we need to look at his opposition. When Jones was coming up, he was a genetic freak with crazy length and reflexes plus a solid wrestling background. At the time, lhw was ran by a declining "old guard" consisting of dudes in their mid-late 30's, all with tons of mileage and injuries. His only win against another elite young gun before the title was Bader, and it's safe to say at this point that Bader wouldn't really hit his stride for many years, and honestly may still not UFC caliber. After getting the belt, his first young up-and-comer was Gus, and that was a heavily contentious fight where Jones took more damage than his opponent. After that, he started going through his personal troubles and fought once a year for the next 5 years: glover (who was almost 40), cormier (a close fight against another late 30's who he had substantial height and reach on), OSP (who's never been elite and was a tune up fight), and Cormier again (who is obviously even older now, and Jones popped for steroids). Afterwards, he faces the ghost of Gustaffson and them two MW (one of which arguably beat him) before Reyes. Fact is, Jones has rarely had to fight another young athletic fighter, and the couple times he has, he was proven very mortal. He's just simply not that skilled in the technical realm (at least compared to other champs), relying on his physical advantages to win fights. Edit: a lot of people are mentioning age as a factor. Jones is 32. For reference, ferguson is 36, khabib is 31, adesanya is 30, stipe is 37, usman is 32, mcgregor is 31, Cejudo is 33, and the list goes on. These guys have all been training in some form of combat sport most their lives. Jones is right in that peak zone.