I just think his game is suited for the next level with more mature and better players overall. He seems to have determination and be a smart player and I do think he will be successful. He just isn't that Lambert, Kemell or say MacKinnon kind of a guy.
Spot on, in my opinion.
Some players are suited better for chaotic junior hockey, players you mentioned are good examples of these. Speed, hands, straightforward thinking, doing ballsy and risky plays. That stuff is what will attract success in junior hockey.
Helenius is total opposite in my opinion. His game is all about brains, knowing where to be on the ice (and when), doing smart and efficient plays, giving space to linemates with smart movement, being aware. He has played against men a ton for his age, so it is no surprise for me that he excels better when playing with older men.
Barkov was like this in wjc tournaments. Was not flashy at all, and people were dissapointed in his game at junior level. I think Helenius' situation is similar. Their game is high IQ, smart decision making, "percentage" hockey.
If you play with men ages 17+, in a competitive and not-developement league, you start to think the game differently than your teammates that play junior. You expect them to have the awareness to see the game in a higher level, on a more tactical sense. Especially if you are prone to play responsible, mature game.
I think Helenius is flying under the radar for most of the fanbase, surprisingly low hype. Similar style player, Anton Lundell got much more attention. I unironically think Helenius has bigger ceiling. He has above average wrister, top notch IQ and decision making, good skating for a finnish prospect, he is very gritty and not afraid of contact for his size. Plays with head up, is responsible, still capable of doing surprising things with the puck (not that cringe tier high-risk stuff that work in juniors but not in the nhl).
I'd say his floor is a 0.5ppg, defensively responsible middle-6 center. And ceiling is sebastian aho tier.