please why not just upload the game here, even if you make it DRM it will still get stolen in steam. why allow Valve a company who does nothing for you and no they do not promote your game, why allow yourself to only one store. we will not be responsible for such actions Valve will take in the future, we can not guarantee your game in steam will be in steam.
the only thing i can say for sure about itch.io is that they will not banned you, you have more chances to earn more here than 30%, actual people not scammers who ask for reviews. If anything consider another platform than just one because if steam is gone, than what will people think of your game after they already brought it.