But programming can be done with less starting-capital than carpentry, realistically.
It gets close when you incorporate hardware as well. Now you can make tools with a software component, sort of a technical blacksmith, but you are still reliant on a fragile supply chain. Perhaps the technological handyman or tinker is as close as can be achieved inside this scope?
Lots of grey areas with many skills.
You say that programmers need a lot of societal components but so does every one of those professions. Unless your kids are learning how to harvest and dry their own lumber along with classical carpentry with nothing but wood joints, they will need a massive supply chain for the lumber and fasteners - unless you expect them to hunt down bog iron and bootstrap all of civilization themselves. Same with plumbers who need PVC/copper/solder and a modern sewer/water system or septic tank. Or the electrician who needs copper wire and power infrastructure (or solar panels, which require semiconductor manufacturing). What good is an electrician without the power plants to feed their customers?
I like your approach but I can't help but feel that unless you’re going full apocalyptic prepper, the practical skills are an illusion.
Traditional woodworking and blacksmithing like that is now mostly a novelty in the developed world. No one really knows how to make their own tools from scratch which is what it’d take to bootstrap carpentry. The best realistic set of skills would probably be knowledge of how to work with fibers to make rope and gather pitch for adhesive. Then you could make a primitive axe that can do most of the hard work in bringing down and hewing trees.
I’m not an especially good carpenter, and I can work with limited tools. A chainsaw and an auger drill would be really nice, especially if I had to make lumber.. but an axe , drawknife , and chisels will do.
That’s like being a programmer that can’t write software without a framework and libraries. The idea is that tools make the job easier and faster, not that you don’t even understand how to do the job, but only how to staple code together. We all start out there, and while we may rarely if ever work that way, we can when it is needed, do something no one has done for us.
Obviously, different trades have different utility if you are talking about the breakdown of society, but I’m not really leaning into that particularly hard, more leaning into the breakdown of one’s plans or expectations, the failure of a company or the evolution of an industry, those kinds of force majure events that one can reasonably expect to have happen during a life lived.
Even so, there is some comfort in knowing that your personal knowledge and value to society is robust and resistant to black swan events, I suppose.
Deserted islands don't have libraries.
Carpentry offers limited applicable skills if they're stranded 1000 miles away from the nearest Home Depot.
These companies are running on fumes. They cut to the bone, through the bone, and everything is being held together by a thread.
But security research is really far removed from the skillset of a startup app developer. Realistically, even if you were capable of learning, which most aren't, it'd take longer for you to get up to speed than it would take for the market to improve.
The more relevant answer would be to bootstrap an MVP and pitch it to investors to get funding to scale. There's no piecework model for consumers like "install can lights" or "build a she-shed."
Mental capital is still capital.