That's because you need to understand the difference between a project and a product.
If you want your product to succeed, it must target decision-makers with a budget to buy your license, and it must make enough difference to them to justify the costs.
Most software libraries aren't products. They target other software developers who are not responsible for allocating funds. Furthermore, if there wasn't a library, most devs would absolutely love writing one ad hoc. Their salary would remain the same, had they been solving the problem from scratch (which most of us love doing) or adopting an existing one. It's the business people that would feel the difference, but business people don't understand the specifics of libraries. And they hate integrating closed-source parts into their codebase because it comes with tremendous risks should the vendor go belly up.
What could sell is a higher-level product that would automate boring/repetitive tasks that everyone hates. Like a GUI designer for some boilerplate stuff that everyone codes by hand (mind you many people like coding by hand, but some hate it and they will buy your GUI).
Your product can also be your consulting business. Don't add stuff based on everybody's requests for free. Make it open-source, welcome contributions, but if someone wants some specific stuff, give them a quote. From time to time, add commonly requested parts and write articles explaining how they work to gain visibility. You will have to deal with lots of entitled assholes, but you will also find people willing to pay you.