itch.io is just a bad site ,it needs someone who knows what they're doing to overhall the whole site.
and yes some scummy devs do use it to promote a game and then give you the finger when it gets on steam.
Arseholes are always ragging on Digital Homicide but they post the steam keys for their games when they hit the steam store.
But if you bought it through Otakumaker site you will get a key from otakumaker in your email