Take a pick (I only list wins here, he obviously also had a lot of podiums):
1969:
Wins TdF, MSR, Ronde, LBL. Kicked out of the Giro. Wins Paris-Nice as only second tier race, I would say.
1970:
Wins TdF, Giro, Roubaix. Second tier-wins: FW, GW, Paris-Nice.
1971:
Wins TdF, MSR, Liège, Lombardia and WCRR. Paris-Nice, Omloop, Tour of Belgium (which was bigger back then) and Dauphiné (which was probably not that big).
1972:
Wins TdF, Giro, MSR, Liège, Lombardia. Also won FW, Emilia, Brabantse Pijl and Scheldeprijs (lol).
1973:
Won Giro, Vuelta (which was less significant back then), Roubaix and Liège (a quadruple I don't see many riders do today). Below those races you have Omloop, GW, Amstel, Paris-Bruxelles.
1974:
Won TdF, Giro, WCRR but no monuments. He did win the Tour de Suisse between the two Grand Tours, though, but not much else.
But yeah. If Pogacar wins the Tour, LBL and Lombardia, this season would definitely be up there. If he also wins in Glasgow, it's probably the best ever season. Unless you weigh a Grand Tour double higher.