Forza Horizon 4, Remnant, GR Breakpoint, NFS Heat, Snowrunner, State of decay 2, AC Odyssey, Diablo 3, No man's sky, risk of rain 2, division 2, Grounded, GTA V, Overwatch.To be blunt, i dont care. Not my problem.
And frankly this statement doesn't hold a lot of water. Most friend gaming groups focus on only a couple of titles at most. I can't think of very many gaming friends I know that play more than 1 or two perpetual games. Which still leaves you with plenty of space for other titles to play on your own.
Plus if you want to go back and revisit a title, then reinstall it.
We are well past the days in which you can just swap cartiridges or discs and have your entire library at your disposal 100% of the time. This is the digital world now and as a result we have to deal with storage limitations.
Name me 10 games you play all at the same time that you have to justify constantly having installed and available.
That's my "ready to play" list, which caters to the interests of my current solo play and the interests of my various gaming buddies.
It's almost like human beings are capable of having different tastes, and that you can play with different people separately.
Also you don't have to care. You expressed not understanding something, and were given a viewpoint to why it happens.