iTunes has most movies and most of those movies are available to rent. New releases usually start as purchase only and become available for rent after a month or two. Star Wars is a special case and is not representative of "most".
So only those who have money should be able to enjoy Indiana Jones?
Your worldview makes total sense...
Thankfully, nobody sane agrees with you. Even Apple doesn't agree with you - its success of the iPod and iPhone is predicated upon pirated music and free access to information (the internet)
I make per-movie purchases digitally through Amazon's streaming service. I have been happy with it. (This is in support of your comment, to say there are services close to what was requested. I'm not trying to say iTunes is bad; it just doesn't work for me, as my "media box" is a PS4 hooked up to my tv.)