19th in the league last year for contested possessions (and the most for Carlton) which is a pretty good effort for a 3rd year player. While his endurance is his strength, it's not like he's incapable of winning the contested ball.I can't see Walsh ever being the best player in the AFL, let alone in 2022. He is too small and doesn't win enough contested ball. Being a great endurance runner is obviously a strength but this isn't the 90's anymore and is less important with rotations and zone defensive structures.
In regards to his size, he's taller than Selwood, Libba, Parker, Mitchell, Laird, Miller, Boak etc. and only 2cm shorter than Petracca. He's not as naturally big as someone like Petracca but he's still just a kid dominating without support. I don't think he'll be the best player in 2022 but I don't see why he can't be in the future.