I would like to buy the game direct from Larian, without any intermediaries. That option isn't available though, unfortunately.

I want to be forced to install and then run the game on a disgusting, Freedom destroying Operating System. I don't think anybody does. Since there appears to be no GNU+Linux support at the moment, the only way to try and play Baldur's Gate III on GNU is to install Steam and hope that the game will run well under Proton.

I sincerely hope that Larian have tried to make BGIII work on Proton and have solved any bugs.