SW '77 was in some ways the same way. It had the typical Wizard, Princess, Farmboy, Bad Guy with a mask, and Smartass Rogue character, all stereotypes, that weren't totally explored because of the standalone movie. Both movies work to perfection because they are basic in their fundamentals of movie making and don't try to be anything else. The simpleness of Star Wars is what I love, it doesn't try to show Vader conflicted, it doesn't show too much of each character that would have overidden the basic good vs evil story.
ESB is much more than that, and that is why it is great. It takes everything in SW '77 and delves deep into every character, but does it in a adult way where it doesnt come off as laughable. The PT and some respects ROTJ tries to be like SW '77/Raiders in telling a story that is a roller coaster ride for 2 hours, but tries to delve deep into a character like Anakin/Padme/Vader and what drives them to what they do, but those two styles don't mix.
Look at every Anakin/Padme dramatic scene in the PT, it comes as laughable every time, because the serial style of movie is not meant to be a character piece, it is a macro story-type movie just like SW '77/Raiders where if you like the characters, you're hooked. That is why many fans like myself can still watch the PT for the popcorn entertainment of them for 2 hours, but laugh everytime they try to get dramatic to give it that emotional weight ESB had. The problem is it is laughable, and it aint a comedy.