Star Wars itself is a retro movie, which sprung out of his thwarted plans to make a Flash Gordon film. Even Raiders is a glorious throwback to cliffhanger serials.
I think seller’s remorse is kicking in.
And not every space movie that came out in Star Wars’ wake was a bomb either.
It’s funny because Lucas says he tried hard to make every film “different” but TPM is as much an ANH rehash as TFA.