Or maybe not. GOG team clearly stated and proved that the service can go down anytime and maybe never return again. That's what we learn with the ill fated GoG PR stunt, and for that GOG can never be trusted on that front.
True lots of people didn't like the PR stunt and I wasn't really happy about it either. But still it was a excellent trial run for what to expect if it did happen. GoG clearly said something was up (even though it was a bad PR stunt half truth), then they said they would enable people to go download all their games they bought in a few days. Since all their games are DRM-Free once you downloaded it was yours to keep forever and could install and uninstall at your leisure even if their service was gone. Exactly what should be expected should an online distributor go out of business IMHO. Since I archive all my games locally as I buy them, even the PR stunt didn't bother me much. The only annoying thing about it for me was there would have been no other alternative to GoG where all games sold are DRM-Free. As for trust, I trust GoG more than any other online digital distributor on the planet today. Since I know once I buy it and download the product, I literally own it and can uninstall / install it at will.
If the same thing happened to any other system I guarantee you all your games would be lost. Even though Gabe has stated a while back that if Steam ever shutdown they'd come up with a solution to enable you to keep your games, I am certain he was only talking about Valve published games not any of the other ones that not only use Steam's DRM but some other third party variant.
GoG is the only place you could be certain that the games you bought are licenses you own
. Steam games you rent or I believe the word they use is subscribed to. You don't buy a license to use the software you buy a subscription to play through steam, so if steam goes, they are completely without legal responsibility to provide a method for you to play the game without the steam service. Almost every other service is exactly the same in one way or another. Either you are dependent on them or if not on some activation server that might disappear in a few years with only some vague hope they will provide you a patch to run the game you bought without the activation server.