I’ll try and keep it short with a bullet list, as I can tend to be long-winded about everything.
Helped recover files on an old laptop in the Win XP days (how I got started).
Breathed new life into older hardware that was too crappy for Windows.
Thought it was neat, novel, fresh, etc.
Free. Why pay for or pirate Windows?
FOSS and, specifically, FOSS alternatives to paid software I’d otherwise have pirated.
Less targeted for malware.
Windows 11 says no to my aging, but plenty capable, computer (the last holdout on Windows til Win 10 hits EOL).
Reasonable, optional telemetry.
Not having to reboot (possibly more than once) during updates.
Fun to learn.
There are some reasons to like Windows, but it’s harder to justify with the direction Microsoft is, and has been, moving.
EDIT: To actually answer your question about Steam and Linux… because I have a Steam account that I’ve had for many, many years with 1000 games that predates me moving to Linux in a more serious capacity. While I could move to GOG (and have), I’m not just going to throw away my game library. But also, Steam working to make gaming more mainstream on Linux is a net positive for Linux in general. That was always the reason many people gave for why they wouldn’t switch - that, and proprietary software that won’t run on anything other than Windows or maybe Mac.