>>720144086
A lot of people kind of overreact when presented with this question, but the biggest reason is because people's motivations and situations in life can change quickly and if they leave, you're shit out of luck if you're only doing rev share.
Solo dev ensures that the project will continue for as long as it is feasible for the developer and only that developer.
It's logistics; while more people ensures that a project (often of greater scale) can be completed in theory, when it ends up being in practice is creating one more weak link on the chain powered. Motivation is ephemeral and delicate like a snowflake, what you need is discipline which is something that everyone has heard before but few people know just how much you need to finish a video game of a certain scale.