New jobs/careers are going to have to be created, as they always have. Go look at a list of the top 20 highest paying jobs nowadays for starters.
High pay = high demand. As things become automated, their price comes down, and frees up capital for more productive enterprises.
Read this article:
https://en.wikipedia.org/wiki/Lump_of_labour_fallacy
There is simply not a fixed supply of work to do in the world. Are you suggesting there is a finite amount of programs to program, things to invent, music and art to create. Have we run out of diseases to cure?
Work = problems. When humans have run out of work to do, we will have run out of problems. That is called a post-scarcity economy and would be a good thing.
All those vague glossed over generalities do not have any connection to the nuts and bolts of the situation. Schumpeter's theory was great while it lasted, but it always assumed a human link in the chain.
All that is being taken way. For every problem, the solution, the 'job' will be done by robots and AI. It will eventually require 1% of the existing workforce to run it all. It completely breaks the circular flow of income. I don't care how cheap it becomes, if you have no money you can't afford it.
Our education system is not producing people that can fit in that new world of technology. You can't fix or invent machines, even cheap machines, if you don't know how. Those people will have little opportunity for making income. And even if they switch careers, we will have a glut of people in the job market, as it will take very few people to produce enough for the existing population. The circle of income/demand will be broken for a very large segment of our current population.
None of this addresses our debt, taxation, or currency issues.