I strongly dislike Steam as a platform, but yeah, as a creator, sell where you gotta.
Also, I love how the headline looks, it seems to say that you will be lonely going to Steam.
The VN will still be free on Steam, so I won't exactly be 'selling' it; it's just another place it'll be available. You don't need to DL it on Steam if you already DLed it on Itch.io, since both builds will be exactly the same.
