I figure that most of the streaming titles will be lost in time. Sure, the equivalent of "Casablanca" will still be available. But series that people are fond of but weren't good enough to win awards .. they'll vanish into the ether.
Either way 500GB for 2 hours is still significantly compressed - over 90%.
Standard UHD 10 bit 30 bits a pixel, even at just 24fps is 384021603024 = 6gbit/sec just for the video alone without audio, ancillary information, and container overhead. I suspect movies work in 12 bit too, and work at 4k, so that's 409621603624 = 7.7gbit/second, or about 7TB for a 2 hour movie.
Not as long as piracy is a thing they won't. It will just be illegal to own them.
If something is removed from netflix, that's fine, I'm not paying to buy things I watch on netflix - I'm paying to rent them. I wouldn't copy them any more than I'd copy a VHS I'd rented from blockbuster back in the day.
At least there, legislation has us covered - most movie, TV and text products have to be submitted to national archives.
There are also large differences between the different streaming services. For example: prime Video is quite bad, while Apple TV+ is quite good.
Then there is also the absolute ridiculousness of Sky Showtime, a brand new streaming services that launched in 2022 without 4k or Atmos support.