You're also paying considerably less (33% less)
Not to mention the steam update is still in early access, so you don't even know that the features won't come here once they're ready
The game is literally the same price, or even a little cheaper on Steam with the current promotion, so what are you talking about? And even then, we're paying for a game to have the same one everywhere, aren't we? I'm not spitting on the development, but I think it's a bit lame to force yourself to release an update just on Steam, ignoring the Itch'io buyers who contributed to this development.