I want to add a little something to think about before you start buying games available on GOG at Steam instead. We'll start with just one word:
Roadtrip
Every time I buy something for Steam, I check if it's available at GOG. If it is, most of the time I pass, and buy something else that's not available at GOG. The reason "Roadtrip" always comes to my mind every time I buy on Steam is because if I travel without internet for a while, it will give me time to catch up on my gaming backlog, BUT, not my Steam games because those games won't work without internet.
My GOG games always work.
What do I do if a hurricane knocks out the undersea communication cables to my little island, so I no longer have internet for 6 months? I will play my GOG games. 18 hour ride on the chicken truck? GOG games work. Spending 3 months in a refugee center due to broken levees flooding my city? Everyone else is miserable, but I'm playing my GOG games.
ROADTRIP! GOG is ready.