Pay per view is not convenient. You have to make a decision each time "do I really want to watch this, is is worth it" and then have buyers remorse afterwards.
Pay a monthly, automatically recurring, fixed fee is convenient. Out of sight, out of mind.
I generally feel the opposite. It's much easier for me to buy a movie or box set outright than subscribe to a streaming service. It's pretty much the same with all fixed recurring payments -- I always feel pressure to use the service and I'm constantly evaluating whether its worth it.
I'm very skeptical about arguments that it's about convenience and not price. Yes, especially outside the US, there is some content that is difficult to get legally for any amount of money. But there's also some upper limit to what I'm willing to pay for physical media that I'll watch once (even if I can acquire it with one click on Amazon) or what I'm going to pay for a monthly subscription even if it were a hypothetical all digitized content ever made for one monthly fee.
Pay a monthly, automatically recurring, fixed fee is convenient. Out of sight, out of mind.