What it seems like you’re asking here is “What does a publisher actually do for a developer?” It’s kind of a complicated question, but the answer is generally “take care of everything except the game’s development”. This does not come free – it generally has a pretty significant cost. This is why some indie developers choose to self-publish – they would rather try to do it all themselves than pay the cost to the publisher. The individual developer/publisher relationship will always vary because it’s all legally contractual in nature. So let’s go over what it is a publisher usually does, and then I can briefly explain the sort of costs involved.