Here are couple of explanations/opinions that I found interesting.
Greg Van Avermaet, former 2016 Olympic champion, with a 2017 Paris-Roubaix among his 42 victories, on Pogacar who doesn't look like much physically, not muscular: "Where does he get his physiological advantage from? They really should examine this guy to understand what makes him so well-built. VO2 max is measurable, but the difference won't be that great compared to the others. How does his body react to effort? And how does he recover? Because in reality, he rides two kilometers per hour too fast. His ability to recover and keep riding, it's
unprecedented," he continues.
"In jest I said to my wife: 'If we put Pogi and me side by side in our underwear and ask someone who doesn't follow cycling which of the two crushes the competition, you'd still say me. I look way more athletic. No one would say it's this little guy,"
View: https://x.com/i/status/2036722736718832000
View: https://x.com/i/status/2035760301899956395
The last one i found the most intresting. I am pretty convinced it is close to the truth, they have some really top notch genetic doping on top of the traditional juice. Never getting tired, no physical limits, dropping everyone at will whenever needed and on all kinds of terrain. Particularly telling is his reaction to serious crashes, his body is not reacting to trauma in a natural way.
I am not the biggest fan of the motordoping theory, but seeing the endless seated power burst, knowing the tech is possible and considering his riding a state owned Colnago, I can't rule it out either. I also have zero trust that UCI would bring it out to the open even if they found something out.
P.S. If you don't speak french the translation option is quite accurate these days.