That's essentially what a rental is. You're stuck with having to stream it, but most people don't care or even know about quality differences from that.
But if you're buying the disc it's not just $20 for 2 hours of entertainment. I bought Spiderverse on 4k and have watched it at least 5 times since buying, sometimes solo, sometimes with friends.
Then there's no need to buy and renting is perfect for you is my point. It's typically 2 to 4 dollars. You can rent from iTunes, Amazon, YouTube, etc and get the movie usually for 48 hours.
Perhaps I really enjoyed the movie though and I’d like to watch it again in a few months time. Do I pay to rent it again or pay $20 for a permanent download?
But if you're buying the disc it's not just $20 for 2 hours of entertainment. I bought Spiderverse on 4k and have watched it at least 5 times since buying, sometimes solo, sometimes with friends.