Linux gamer here. Steam is unique in its continuing efforts to capture the Linux gamers.
Valve is the primary publisher making linux gaming reasonably viable. They manage Proton, which gets most games going. They have first party support for their client. Their client allows you to download games not marked as explicitly compatible, and they track linux users in the steam survey.
Yeah, Microsofts uncertanty has been a boon - but Valve's efforts have set the foundation needed to take advantage of it.