Making the star wars prequels solely for monetary gain was a sellout thing to do, not making those other non star wars or indiana jones pictures and making only safe sound business ventures was also a sellout thing for a so called maverick anti Hollywood guy.
He is a great businessman, his value as an artist once he started making Hollywood style films with star wars and not making those types of films he would have made at Zoetrope that never happened is a matter of opinion.
Personally despite my hatred of the special editions and the prequels i am happy how things turned out minus the selling of Lucasfilm to Di$ney.
Had he directed Apocalypse Now and it had bombed he may have never directed again and star wars would not exist.
The advances in film technology, cgi, digital sound and editing either would not have happened. Unless someone else did it.