As
@QueenStagiaire said, Pogačar wasn't necessarily focused on Liège given that it came just 2 weeks after the biggest win in his career. I wouldn't argue that Van der Poel was focused on Lombardia just because he rode it in 2020 either.
Just some stats, Pogačar has 6 monuments wins out of 14 starts while Van der Poel has 6 monuments out of 18 starts so Pogačar has been clearly the most effective of the two on the biggest WT one day races.
Van der Poel has one thing that in my opinion puts him up there with Pogačar though, his World title last year. However even in major Championships, Pogačar has already a bronze medal on both the Worlds and the Olympics.