In my opinion AI isnt the biggest threat in the near future, its machine learning. Just having a machine move from being able to do a simple one function task to a multiple conjoined function task will revolutionize the work force, and it is coming within the next few decades. A machine that can be rolled out to tackle simple tasks on a massive basis and also one that can be updated so in person fixes are almost never necessary is going to be created. There are already many plans for companies creating simple all purpose machines that will have a vast amount of possible use cases.
Modern Keynesian economics says that with the replacement of jobs in new industries, more opportunities will be created in the long run, but this might not be the case so much in the future. If you look at the top 5 revenue per employee ratios, you see it is all companies that hire mainly programmer jobs. One could argue that these companies per employee are so profitable because it is the nature of the tech industry, but one could also say it is because far fewer people are able to produce on a much larger scale. The amount of employees needed to reach a large market of consumers is shrinking, especially with new companies.
While before you needed a single cobbler to make a shoe and repair it when the soles wore down, a company can have one machine build 50,000 phones in a day and a group of 5 programmers can fix a problem remotely that will go out to millions. Simply put, less employees are going to be needed as we move more towards a future more integrated with machines and when we hit the point of usable and practical AI, most human jobs will become irrelevant. Similar to how computers started out mostly as single job processing machines and transformed into multi purpose devices, I believe we will see the same sort of transformation in the robotics field.
I don’t think past economist could have imagined a world like the future we are living in now. In the near future the creation of a new industry might just create new jobs for machines that can do a much better job than a human can, which is another concern. What if you create an industry job that another computer might just be better at doing. Rather than having a tech person fixing machines, you create a machine to fix machines. The only time you need a human to do it, is if the machine that fixes the machine breaks, which could be very rare. This all gets very complicated quickly and goes further down the rabbit hole, but still isn’t completely out of the box.
In my personal opinion we are going to eventually have to change the way we think about economics. Im all for moving forward and maximizing profit in anyway we can because if we don't, someone else will, however that being said, without any type of safety net for the people who will be replaced, we risk severe threat of a breakdown of modern society. People without a reason to live or jobs to work, will resort to violence if they are unable to feed their families.