From the opinion piece:
Last year, I pointed out how many big publishers came crawlin’ back to Steam after trying their own things: EA, Activision, Microsoft. This year, for the first time ever, two Blizzard games released on Steam: Overwatch and Diablo 4.
GOG > itch.io > Steam > whale poo > everything else
For Linux, it’s Steam and then anything that works with Bottles, Lutris or Heroic.