Buying isn't owning from literally any game company. When you buy digital you own a license to play that game. The license can be revoked at any time.

When you buy a physical game you still only buy a license to play that game, and the license can be revoked at any time. The only difference here is you own the physical disk that media is on, and it's harder (not impossible) for the owner of that media (the one who sells the license) to revoke the license to that media.

I appreciate that people are pissed about this but it was a thing before digital media took off and the only difference between a steam game and a game from Epic is the inclusion (on Epic) of an offline installer store that allows you to install the game without connecting to the internet.

It's the same license.

I'm also going to add the PlayStation, Xbox, and even Nintendo have removed titles from people's libraries when their agreement to license the media to the users lapsed or were removed. So it's not just Valve.