Amazon at least here in Germany offers either to rent or to buy. Now whatever their ToS say, there is a certain expectation to the word "buy" and I'm fairly optimistic that courts here would take a dim view on clauses in ToS allowing a one sided revocation. Even if it is only a license to stream it is a property right. In B2B one may put some twisted clauses into contracts but in B2C such attempts are regularly reigned in.