>>116426093HxH is about the characters relationships. Gon's journey is one of self-discovery and loss of innocence; at its heart HxH is a coming of age series, more than almost any other fighting shonen out there. His motivation is perfectly reasonable, he wants to meet this legendary figure that is his father, a guy everyone seems to admire so much yet for some reason never bothered to visit his son; his Nen ability is simply a means to an end, he's not trying to make a SUPER INTERESTING POWER WOW SO CLEVER, he just wants something that will be good enough to get him to his goal.
His "obligatory super transformation" is also a gigantic trope deconstruction; he gets to do it once, at a HUGE cost (literally sacrificing all his nen potential forever), and for all intents and purposes for a completely selfish and pointless reason: simple angry revenge.
And the most important part: his arc ends. He has a completely, satisfying journey from beginning to end, and by the end of the anime Gon's story is told.
Hunter x Hunter is extremely well written, you'll have an extremely hard time finding other shonen shows that reach this level of competent character development and long-term plotting.
