Give me any example of Valverde doing any Grand Tour all out, going for multiple attacks, long-range solos etc... It was mostly surviving in the mountains and sprinting for the stage from a small group. With all due respect, that can not be compared to the way Pogacar rides... Valverde's style was far more energy-saving.

Doing the Vuelta is a bad idea from next season's perspective. Riding all three doesn't add up his chances to win the 2025 Tour or who knows one more Giro-Tour double.
As already said: It wasnt only Valverde.
But even talking about Valverde. Pogacar seems completely in control and doesnt need to go in the red during the mountain stages while Valverde was at his absolute limit on most days. So you could also have a different look at it.
But anyway, I dont believe that Pogacar will try the Giro/Tour double again next year. If he doesnt ride the Vuelta this year, as should be expected right now, a Tour/Vuelta double is probably much more likely next year.
Pogacar said he wants to be remembered as the greatest of all time. Winning all grand tours in one year would be a milestone on his way to this target. Winning the worlds once doesnt do that much for his palmares. Winning Milano-San Remo and Paris-Roubaix would be another milestone but right now seems much more unlikely than the triple this year. Worlds, Lombardia, Tour de France etc., he needs a lot more wins to even get close to someone like Merckx.
In the end I dont think Pogacar will do the Vuelta this year but I think that would be a mistake. No one knows how much years he has left at the top. Strong riders are upcoming and a career changing injury can occur every day.