Most people who publish through major publishers aren't making much either and publishers these days don't do a lot of promotion for authors who aren't already well-known.
They do provide sales and distribution and if you're writing mostly for reputational reasons, those may be good reasons to do with a "name" publisher.
But, if you're focused on trying to make money and are prepared to make a speculative investment in making it, it's not at all clear to me that you shouldn't self-publish and pay for promotion, editorial services, etc. to try to make it happen.
Authors have a lot better alternatives than mobile app developers who have basically no choice but to pay the app store tax and musicians who are significantly limiting their reach if they opt out of streaming.
