Well publishers(Depend on the contract between you and them)they pay for marketing and for the development cost they handle Law stuff they even influence the Development progress(As far as i know)
Viewing post in Why Developers Stay Solo?
that would be the ideal situation
but in practice as a solo dev you usually have very small development costs
so with a publisher you essentially just paying a bunch of people
that tell you that your ideas suck and you should implement theirs
and then somehow end up shipping your game prematurely
because they also set the publishing date 🙄
I guess I'm a bit cynical about the whole thing .. 🤔