i did not recommend releasing on steam. i wanted to point out that you are basically unknown on itch. no one will buy your game, if they do not know either you or the game. so a demo version is highly recommended on itch, even if the same developer might not have one on steam.
on steam the users have two things that itch does not provide, that will make them more likely to buy from unknown developers.
they can give it back within 2 hours, no questions asked. and there is a certain level of quality standards a game must meet to be published there at all.
if your game is not an online game with a login, i misread the descriptions either on the page or on your website.