This is from McKeen's, one of the best scouting services available and one of the 5 I refer to most when wanting to affirm or counteract my own opinions after watching a player. The reason I source them now is because they are the only major scouting service which grades individual skills numerically, on the 20-80 scale. First, their rating on Kakko's shot:
Shot: He has a quick wrist shot that can beat goalies cleanly. He can shoot the puck with good power and accuracy. He is dangerous around the net and can score from close range. He plays with an unusually short stick which doesn't benefit his shooting. On a more positive note, he has started to shoot the puck more in the Liiga as the season has progressed. A constant scoring threat in the offensive zone, Kakko has the ability and potential to be a good goal-scorer in the NHL. Grade: 60
Obviously, McKeen's thinks the same as everyone else on the planet -- that Kakko has a very good shot and will be a very good goal scorer in the NHL. To give reference to the numerical scores, "50" would be average (for an NHL-er, so not a weakness per se), 60 would be a very good tool, 70 would be absolutely elite, and 80 would be like a super power, very rarely given out for anything.
With that in mind, here is McKeens view on Jack Hughes' shot:
Shot: Even Hughes’ worst offensive tool, his shot, is well above average. He is much more a playmaker than a shooter, so you can see his goal totals being dwarfed by his helpers. He owns a very strong slap shot, and his wrist shot is likewise a legitimate tool. He does get his shots off, averaging more than four per game in USHL league play, but as often as not, they do not look like they are intended to score on their own, but rather in preparation of a more sure fire scoring chance for a teammate. His shot is quickly released and sustains plus velocity. Grade: 60
I repeat, "even Hughes' worst offensive tool, his shot, is well above average".
I appreciate your debate about "what makes a generational player", I think that would be an extremely interesting discussion. I also think it's a very intriguing parallel you make between Kakko and Barkov. But we need to put to rest the myth that Hughes has a weak shot, it's simply untrue.