At a certain point, if you want to be really successful, you will be forced to leave certain things to other people. This is a collaborative business for a reason – because virtually nobody can make an amazing sounding record entirely on their own. That’s why you virtually never see only one name in the credits of even halfway decent records. So at some point you start hitting a brick wall with the quality of your music and you realize that if you are going to go any further, you will need to bring in talented people who can do certain things better than you, or to simply bring in another set of ideas so you can double (or triple, etc.) your creative energies.
It’s amazing how many insanely talented artists I’ve met who could never put out a decent sounding product because they insisted on being the only songwriter, producing themselves, recording themselves, mixing themselves, etc. So doing everything yourself is fine for trying to grow your skillset. And it’s fine for your releases provided you don’t expect this to be anything more than a hobby. But once you turn the corner and decide to try to make a job out of being an artist where you actually make some profit, then you pretty much will never be successful unless you rely on other people. Yeah, there are a couple examples that defy this, but they are generally anecdotal.