I sort of work in the industry so I feel like publishers are pretty important in getting your game out there. You, as a developer, want to focus your energies in making the best game possible. To make a game successful, there is a whole gamut of tasks which are necessary but are a pain to do such as finding a QA team, finding someone to do localisation, porting your game to other platforms if needed, marketing, and in a good bunch of cases providing funding.
The last part is where things get ugly. Because publishers are the ones who are giving you the money to complete your game, you are naturally beholden to the timelines and goals that they set. Good publishers listen to the developers because good games make good money. Then there are fucks like Sony management here and whoever was at embracer group who have never played a game in the last ten years and are in the position because of their MBA degree. There are a bunch of decent publishers out there like Devolver but naturally they are going to be picky with their titles. For the vast majority, going with whoever is going to give you the money and support is the way forward.