Pogi doesn’t have to go as deep as he did to win in both GTs this season. If he were to dial it back with sufficient measured efforts he could cross all three GTs effectively with the same condition as this year.Giro/Tour/WC, or the 'ciciban triple' as they're calling it in knowledgeable circles nowadays. The real one with the Vuelta could be physiologically impossible given how good you have to be in the tour to win nowadays, even Pogacar said his body shut down.
And the treble of GTs never crossed the minds of anyone as a goal until now because it was unthinkable. Two others did the same season GT double in literally half the entire history of cycling. Fair enough the veulta wasn’t always positioned well on the calendar or significant as a race in cycling history. But it has been quasi possible in more recent history.