I have 223 Steam games, but I've not played many of them...I get carried away in the sales sometimes, and as I only got a gaming laptop last year, I still have a lot of catching up to do. But an immense backlog outside of Steam that tends to draw my attention first, because I use my laptop for other things.
I'd use something else if there was anything else, but I find GOG annoying to navigate and I've not really done any research to find out what else is available...doesn't seem to be a lot of point. I don't much care about DRM because it's never really impacted me, and until it does I plan on ignoring it.