He can't match Merckx greatness.True but only in terms of greatness not best. For instance by palmares alone means Roglic is twice the GT Vingegaard is, thats not how black and white we measure the best. Vingegaard been on a level Roglic never reached in terms of GT alone and clearly a better GT rider.
In terms of best of all time Pogacar has already cemented himself as the nr 1 of all time by a huge margin even - already. That part is already piss obvious (theres not a serious guy on this forum even who thinks Merckx is even half the climber Vingegaard is, nvm Pogacar who is many levels above that again or that Merckx would beat MvdP in Flandern) and as mentioned already a forgone conclusion within cycling and big profiles/legends/riders already saying it as the most obvious thing, every objective person would reach that conclusion and its already the case and happening right infront of our eyes. Its so special to witness this big part of history in real time and the guy is still 26 years old, its so rare.
In greatness terms indeed he is still young and need to add more longevity to match Merckx palmares theres no doubt about that but make no mistake theres never been a better rider than Pogacar in the history of the sport after this season, its undeniable.
Merckx was more complete because he was not just a climber, puncheu, time trialist, but also a sprinter.
Besides that, he won Paris Roubaix. Pogacar never won Paris Roubaix.
He also won 7 MSR. Pogacar never won MSR.