Tell me, when was the last time you visited your shoe cobbler? How about your travel agent? Have you chatted with your phone operator recently?
The lump labour fallacy says it's a fallacy that automation reduces the net amount of human labor, importantly, across all industries. It does not say that automation won't eliminate or reduce jobs in specific industries.
It's an argument that jobs lost to automation aren't a big deal because there's always work somewhere else but not necessarily in the job that was automated away.
There is a whole lot of marketing propping up the valuations of "AI" companies, a large influx of new users pumping out supremely shoddy software, and a split in a minority of users who either report a boost in productivity or little to no practical benefits from using these tools. The result of all this momentum is arguably net negative for the industry and the world.
This is in no way comparable to changes in the footwear, travel, and telecom industries.
What changed in the last month that has you thinking that a demand wall is a real possibility?
We lost the pneumatic tube [1] maintenance crew. Secretarial work nearly went away. A huge number of bookkeepers in the banking industry lost their jobs. The job a typist was eliminated/merged into everyone else's job. The job of a "computer" (someone that does computations) was eliminated.
What we ended up with was primarily a bunch of customer service, marketing, and sales workers.
There was never a "office worker" job. But there were a lot of jobs under the umbrella of "office work" that were fundamentally changed and, crucially, your experience in those fields didn't necessarily translate over to the new jobs created.
But the point is that we didn't just lose all of those jobs.
New jobs may be waiting for us on the other side of this, but my job, the job of a dev, is specifically under threat with no guarantee that the experience I gained as a dev will translate into a new market.
But like, if we're talking about all dev jobs being replaced then we're also talking about most if not all knowledge work being automated, which would probably result in a fundamental restructuring of society. I don't see that happening anytime soon, and if it does happen it's probably impossible to predict or prepare for anyways. Besides maybe storing rations and purchasing property in the wilderness just in case.