A good point. Mine is 13 years old, and I've never once had a UX issue with the company where I felt that I didn't own the game. I know that the Terms of Service makes that possible, but in practice, the company's track record makes me delighted to do business with them.
Seems pretty cut and dry to me - you don't own the game.
A. General Content and Services License
Steam and your Subscription(s) require the download and installation of Content and Services onto your computer. Valve hereby grants, and you accept, a non-exclusive license and right, to use the Content and Services for your personal, non-commercial use (except where commercial use is expressly allowed herein or in the applicable Subscription Terms). This license ends upon termination of (a) this Agreement or (b) a Subscription that includes the license. The Content and Services are licensed, not sold. Your license confers no title or ownership in the Content and Services. To make use of the Content and Services, you must have a Steam Account and you may be required to be running the Steam client and maintaining a connection to the Internet.