The only point at which consumers stop demanding is when they die.
People won't die if they won't buy cars, smartphones, luxuries, movies, music, go to fitness, yoga, beauty shops etc!
Which won't happen in socialist communities because they will eat themselves first. Long before technological unemployment is actually a concept, let alone a problem.
Currently there are no truly socialist communities in the world, therefore it cannot happen in principle. But for the most developed countries (which are all free-market capitalist now) technological unemployment is knocking the door. Don't believe?! Look at the U.S. labor participation rate since year 2000.
Look at the example you're typing on. It put a lot of professions out of business. Yet it CREATED hundreds more. Possibly thousands, given the flexibility of the Personal Computer.
We are not going to be outcompeted by robots. We will adapt. We always have, and we always will.
For many people it is just hard to understand what is an exponential growth curve (technology advancements follows it). No doubt new jobs will appear, but after some point their number will be less than jobs automated.
Capitalist, yes. Free market? You seem an intelligent dude, so I'm not going to behead you for that ignorant remark. The only free markets in the US, and most developed nations, are referred to as "black markets" by the media. And they are indeed prosperous. The rest is regulated unto death. A great deal of the lack of labor participation in the US is due to the fact that if you try to engage in any sort of commerce without a small to large fortune backing your endeavors, the barrier to entry via licensing, inspections, necessary bribes, ad nauseam make it nearly impossible. In a free market, the failure rate would be higher, but the losses generally smaller, as the barrier to entry is essentially skill and guts.
Also, of note in your own reply, yes the most developed nations are capitalist. Funny how that works, isn't it? I'm not speaking theoretically when I say socialist societies eat themselves. I'm old enough to have observed it, multiple times. The Soviet Union achieved rather more than most of them, but in the end the necessary contradictions of "public" ownership, as opposed to individual ownership, led to their demise. Socialism is a beautiful concept, if you don't look too deep. It works great for ants, bees, and the Borg. But humans are NOT faceless, replaceable parts in a giant machine. Trying to make us be leads to failure.
The problem you present is real. And yes, I do understand exponential growth (and it's limits!). But the problem is not insurmountable. For one thing, technological advancement does not happen all at once and all in one place. Thus when a certain threshold is passed in one place, those in others observe, react, and where necessary, change course. In a truly free market, this is a quick, dynamic process. In what passes for markets now, it isn't.
The one thing I have in common with socialists is a hatred for the corporate dynamic. Not so much how they organize things, that works, but the very concept of a juridical person. It absolves their leaders of responsibility for atrocious acts. It is exactly the same bullshit as "sovereign immunity" in yet another scam: Central government. Remove the latter, and the former no longer have the patina of legitimacy conferred by the status of Juridical Person. Once that patina of legitimacy is removed, they either have to let the people rise, or show their true colors and raise armies to keep us on their treadmill. Ultimately, the corporatism of the modern age will fail, and when it does, strong individuals will find ways to solve their problems. The weaker or less motivated will emulate them, and we will start making more, different problems for ourselves.
We are a young species. We have come far in a short time, and yes, these issues need to be addressed. But let's not base the solutions on things that have already been proven a failure.