If you want to compare him to someone from the past I would say Greg LeMond. He's the relaxed, flamboyant guy, very good at a very young age, it seems to come easily, and he took yellow in the final time trial. I advise him to avoid hunting parties.
As a French-American, I approve this comparison. LeMond was on the way to a legendary career had he not gotten shot. As it was he merely had an incredible one.
I can't argue with any of the superlatives attached to Pogacar, but I'd say only that he's not yet been as dominant as he could be. He barely won the Tour last year, he hasn't won this Tour yet with crippled rivals, and Roglic has looked just as good in weeklong races, and has won a few big one-days. And recall that Bernal was on a similar GT trajectory (TT notwithstanding), got injured but still has 2 of the 3 GT prizes at age 24.
But yeah, all things being equal and barring bad backs, errant road furniture, clinic issues or hunting accidents, he's on his way to a better palmares than anyone I can think of in recent memory, because there's a lot of classics he can win -- and he seems to like them -- plus (at this point) as many GTs as he wants...surely he'll get a RR WC, maybe even an ITT WC...