There is a difference, though. The majority of these guys are specialized GC riders whose clear force is climbing. Pogacar not only climbs better than the best climbers, but he can also sprint with some of the best sprinters, he can time trial better than the best time trialists, and he will beat the van der Poels, Van Aerts, and Pedersens on the cobbles to top it all off.
Credibility is a spectrum, in my opinion. When pure climbers start contesting the times set by Pantani and Armstrong it's not completely out of the realm of credibility to chalk it up to the huge steps taken in terms of especially training and fueling. But when one guy is so clearly the very best at genuinely everything, the alarm bells have to go off big time.
Pogacar is basically climbing like Pantani, while still having the acceleration of Sagan and the peak watts of Cancellara. That is just incredible - as in not at all credible.