On the other hand you can back up a DRM free download, like the games on GOG, despite these being a purely digital download.
So overall I don't think the physical form matters that much compared to DRM.
Beyond that, Steam and the digital media model allowed a great many people to publish games that wouldn't otherwise have been able to publish games. It made the indie world of games possible. It also did more than anyone to bridge the platform gap between windows and linux.
Otherwise, it's just a pain. Like my favorite PC game Age of Empires 2 was a CD, then when they finally remade it, it was like oh you gotta sign up for Steam first, and now you gotta launch this adware to play your game, which btw is an entire Chrome browser, and sometimes it'll refuse to launch your stuff too. Then several game publishers made their own Steam-like launchers except even worse. The situation is worse now, good thing I don't really care about video games anymore.
I can see a bean counter making a very convincing case that it's cheaper to go back to Windows and avoid all this Linux reverse engineering gubbins which isn't bringing in an immediate profit, especially when they're giving away all theirs efforts by open sourcing Proton.
He's got children to consider and could reasonably want to set them and his grandchildren up for generational wealth.
Granted, his money, he can do as he pleases, but the Newell dynasty already exists, regardless of what happens to his shares.
But Steam is also more annoying than it needs to be, especially forcing updates and not letting you transfer games so it's not comparable to owning a disc.