You said it! Valve actively supports OSS and that in many projects from which people beyond games also benefit (yes, they also exist). That Valve with Proton has just made sure that MS monopoly position is no longer so secure (oh wonder that in the most popular games devs then simply turn off linux support in anti-cheat...). ). You can certainly criticize a lot, but valve gives back a lot of things differently. Just no other Play Störe alternatives because the competition only complains, offers a junk launcher with dubious methods to offer a game for free every week... ( no risk but because of fixed amount possibly significantly less the developers... besides, the money comes from fortnite addicted children ). epic ubisoft ea use dirty methods anyway and known 30%... what they are hiding is that the 30% is the case with steam keys. however, they also have the possibility to link it to their own store with their own keys while it would be listed for free on steam only they would have to do without any steam feature ( anti cheat, workshop, forum, support, download from steam depotetc. Oh and have enough servers themselves regarding downloads.

By the way, about your comparison with android... Take a look at their Chromebooks. Have fun gaming!xD