But many (most?) of the jobs created by airlines, radio, etc, have a low barrier to entry and are easily replaceable. I could be wrong since I don't know what t

But many (most?) of the jobs created by airlines, radio, etc, have a low barrier to entry and are easily replaceable. I could be wrong since I don't know what technological breakthroughs will come in the next few decades, but my educated guess is that the new wave of job opportunities will be much more specialized and require higher levels of education, like engineers and scientists. And aside from the sheer difficulty of transitioning into that kind of a career without prior education/experience in the relevant field(s), it's unlikely that the market will need as many people to fill those shoes. So even if everyone that holds an obsolete job now could make the transition, there wouldn't be enough market demand for all of them to find jobs. Again, this is all speculative, but I just don't see a likely scenario in which enough low-level jobs are created to replace the ones that are lost to technology and automation.