Maybe that's part of the problem. Luke has become a massive cultural icon. Perhaps we're seeing things in his character in the OT that aren't really there.
And I would posit that it was a pretty good arc.
In A New Hope, we meet a young, idealistic, whiny, brash and impulsive Luke who wants to escape his boring home life. Unfortunately, adventure is suddenly thrust upon him when the Empire burns his homestead and kills his family. At that point, the only thing he has left is Ben Kenobi and his vague ideas about "the Force". Luke gets catapulted headfirst into the crazy adventure on the Death Star, finds a foil/friend in Han, falls in love with Princess Leia and then suddenly loses his only remaining mentor figure. At the climax of the movie, Luke loses his last remaining link to his childhood (Biggs) but finds a new family with the Rebellion.
Empire Strikes Back puts Luke through a great deal more trauma. He gets Mauled by a Wampa, crashes his snowspeeder, fails to life his X-Wing out of the swamp, gives into temptation in the cave (this part will be important later), and recklessly runs off to try and save in friends. Empire ends with Han in Carobonite and Luke having lost a hand while trying to deal with the emotional bombshell of his biological father being the most destructive being in the galaxy. Talk about complicated paternal relationships...
In Return of The Jedi we jump ahead a bit, but notice the framing of how Luke is introduced.
Rob Hilton said it best when talking about his Episode 4-5-2-3-6 "Machete Order" :
If you're looking for a fresh way to experience Star Wars, I recommend reading his full write-up. I'll be trying the order myself soon: