No, actually, Gohan is probably the best character with highest potential
It's just that Super and its creators are fucking retards that they live on old glory, meaning only Goku and Vegeta matter, with Vegeta being the most horrible rival out there who's basically stuck in "damn Kakarot, always one step ahead of me". That's to what Vegeta's character has been reduced to, it keeps going in loop.
Gohan said his goal was to achieve ultimate form no one has seen yet. They should've kept developing his Mystic Form, or, they should've let him have Ultra Instinct.