On paper it is unbelievable, but if you've actually seen the race, it was just like 3 years ago with Pogi vs. Roglic. You could just see that Roglic wasn't on his best day ever, and Pogi was. The same happened today. Add to that Pogi's inferior bike handling, losing a second in every corner, and this time gap isn't actually that unbelievable.
Losing a second in every corner? Pogacar was annihilated uphill and lost over a minute in the last 6.5 km (and also likely 10 seconds on the first climb).