Everyone has their days, it's not easy to compare riders based on results because a one-day format is so different from Grand Tour overall or even individual stages, and that's just in road racing. Multi-disciplined riders like MvdP, WvA, and Vos are impressive but there are times when others can still beat them (mountains in the case of all three).
Then there's Pogacar, who has looked unbeatable uphill and even in TdF time trials, establishing himself with authority as the new Grant Tour top dog. I just read that he has
never lost a stage race where he's taken the GC lead at any point.
In the pantheon of top riders, how about reigning World Road Race and Time Trial champion Anna van der Breggen singlehandedly
eliminating 12 riders yesterday? She's out-Pogacaring Pogacar. Granted the women's field isn't as deep with the Giro having been demoted and some looking to peak for the Olympics, but daa-yum.