cleaner667: I joined GOG in Jan 2019. In that relatively short time my GOG library has not only matched the size of my steam library, it is almost double the size. I now purchase from GOG as a 1st choice and Steam 2nd, instead of the other way around originally.
I joined GOG in May 2017, though I became aware of them back in 2008/2009, but due to my web connection back then, I wasn't really able to utilize them, plus I wasn't sure how legit they were, and at that time I did no Internet purchasing, wasn't setup for it.
At that time, the rise of Steam just simply put me off buying games for many years, console games for my kids aside. I was re-introduced to GOG back in May 2017, and the rest is history.
Since that time, I have almost exclusively purchased games from GOG, though a few also from the likes of the ZOOM Platform, Humble Store and Itch.io and a couple from Epic.
Because I had been tricked initially into using Steam (too late to do anything about my disc purchases by the time I realized what Steam was), and because my PC and web connection had improved a lot, I also re-activated use of my Steam Account in 2017, and because I was in for a penny, I decided for a few games at least, to be in for a pound as well. Chiefly that was buying the Valve Collection for a very very cheap price, though I already had some of the games, plus later on purchasing some Tomb Raider games and a couple of Total War games via Humble. Most of those Tomb Raider games I have now re-bought recently at GOG ... as soon as they became available here, and talk about cheap.
Overall my GOG collection is about double that of my Steam collection, and unlike my Steam collection, I paid for most of my GOG purchased games. Most of my games at Steam are free ones.
Disappointingly most of my games at Steam are not listed as DRM-Free, though I suspect that may just be a listing issue in many cases.
My preference is to never buy at Steam, though the exception happens ... like the Duke Anniversary Edition going very cheap. I never look for new games at Steam, never risk tempting or disappointing myself. Just like I never look at expensive AAA type games here at GOG.