I'm a professional woodworker. One-off tables in a garage might not be a great business, but millwork, built-ins, and cabinetry in homes is a great business. You're likely not exposed to cabinet or architectural woodwork shops that build high-end homes, or that just do renovation for that matter.
In case of woodcraft, there is some tangible result that can be appreciated and displayed as art. In case of custom software, there is no such displayability.
It’s not that nobody needs cabinets or doors. It’s that automation, transportation, and economies of scale have made it much cheaper to produce those things with machines in a factory.
I'd like to see numbers backing that up. My personal impression is that you have a small number of custom woodworkers hustling after an ever smaller number of rich clients. That seems like exactly the same problem.