You said it: you are working on a "program for yourself". Hobbyist craft programming will always be here. The question is what kind of software engineering will be paid for, and a career can be built on.
I don't see much of a market for pure software engineers anymore. You also need to be a product manager, scientist, or have some other domain knowledge adjacent to software that relates to the real world.
I say this with empathy for those who just enjoyed the craft of designing and building software, and thought that alone would provide them a livelihood and career in perpetuity, but have found a big chunk of what they loved doing (and getting paid for) overtaken by AI coding agents.
it's hard to trust a claim about someone writing "bug-free" and "extensible/maintainable" code from the singular developer and user for that system... maintainability can't really be a thing you can judge when you're not a single step removed from the person who built it in the first place - maybe you'll feel different if you have to pick up the project again after a couple years' inactivity
I think I've built like 3 things in my life which I consider to have good design. Sadly they are tucked away in private corporate repos. Design is hard!