Again, your problem is seeing the rich capital dominated business market as the only market.
There's an inherent market your skills will always be useful to: yourself. Base survival, maintaining your home, caring for family and friends, improving quality of life - there's plenty of demand there and work to do. The cost to deliver that demand will demonstrably be far lower than it ever has been with these new tools. Would you be able to hire that labor out to corporate AIs for even cheaper in absolute costs due to the benefits of mass production? Sure. But providing these things is a job for you too and it's "free" with just a bit of time and effort.
Tinkering with open source tools to assemble your first robot kit out of older hardware and 3D printed materials is not going to be prohibitively expensive. The cost to train it - probably not either, if the massive efficiencies we keep finding in models keep lowering and the community keeps sharing model tweaks. Make one robot with good enough dexterity and your second bot is a hell of a lot easier to make. These aren't going to take some ridiculously unheard-of materials or manufacturing processes. In fact, cheap AI chip alternatives to GPUs can be built on decades-old architectures designed to just maximize matrix multiplication with much simpler manufacturing. Monopolizing scarcities here isn't a sure bet. We've just been waiting for a good general-purpose brain. We have it now - and every bit of information we expose it to, the easier it gets to do anything with it.
Unless the big fancy AI wielders are coming for you with killer drones by then, this is all stuff people are going to be well-capable of while unemployed and living off food stamps, savings, or remortgaged houses. If they don't have the skills personally, they'll turn to friends and family who do and find mutual tribal support in tough times as people always do. Growing your own food, building your own infrastructure - all have been doable for a while, but are about to get stupidly easy with a few bots and helpful AI guidance. Normal humanity will carry on and pick up the pieces just fine in this new Dark Age, even as the corporates take the open field opportunity to chase for riches beyond our comprehension, mining asteroids and claiming the solar system.
Now imagine if those greedy corporates happened to just throw the rest of us a bone - 1% of their exponentially-increasing profits - as a PR gesture. Still would soon become far more wealth in absolute terms than the common people have ever seen in the history of earth.
If you think none of that is going to happen, then the alternative is a lot closer to the first people with AGI simply scouring the earth in a paranoid culling. Sure, it's entirely possible. But it takes a certain Next Level of Evil to make that happen.
And all that aside - if you really want to play up the capitalist dystopia angle, there's still plenty of individual value to be mined from people via a wage. Memory and preference mining, medical testing, AI fidelity comparison - plenty of reasons to pay people a little bit to steal what's left of their souls for even further improvement of AI. Might be enough for them to afford their first robots, even.
But by all means - go destroy corporate AI data centers if you think you can get away with it. Anything to tip the scales towards public / open source AI keeping up. But this tech is not going away, nor should it. It could very well result in unprecedented abundance for all, so long as things don't go ridiculously extremist.