Soooooooooooo is MHJ a better dynasty WR than lets say.....Puka Nacua? Terry McLaurin? Nico Collins? Michael Pittman? Im not sure the logic of "has done more in the NFL" actually tracks as a valid argument even when the time difference is significant. Based on that logic MHJ is probably not even in the top 15 WR's. But let me take it in another direction......
Imagine comparing 2021 Amari Cooper to 2021 Justin Jefferson. Sure JJ had a great rookie season...but based on the aforementioned logic Amari Cooper had been doing it for 7 years up until that point. At what point did anyone take Amari Cooper over Justin Jefferson in dynasty? Maybe before the season started. Maybe a couple of weeks into the season. But surely not for very long. One year isn't long enough to say "someone has done much more", especially when the numbers don't support a significant difference being present. And even when someone has been doing it longer, unless the levels of production are significantly different, its moot either way because most people would rather have Justin Jefferson than Amari Cooper simply based on age.