To me that just shows that the stat is not relevant to how good the QB is at the thing being measured because Mahomes has the best deep ball in NFL (save for maybe Rodgers) and I do not think anyone would argue that point.
idk - i mahomes probably throws the longest deep ball (maybe josh allen can throw it further but idk that it matters lol) and he can do amazing things with his arm strength and arm talent generally
but russell wilson and aaron rodgers are the 2 i'd say are the best deep ball throwers in the league right now - in terms of deep ball throwing i'd also have deshaun watson, kyler murray and probably matt stafford ahead of mahomes as actual deep ball throwers right now
so i guess i would argue that point lol
there's more to deep ball throwing than just having a cannon and an offence with a ton of fast guys
mahomes is pretty special - but it's not because he's an amazing deep ball thrower tbh