When an individual company looks to increase profit margins they can either increase the price of their product or reduce the cost it takes to produce it. For the vast majority of companies the primary cost for their product is labor. Employees require a living wage, health care, paid time off, and also create additional costs like payroll taxes and an entire HR department.
With automation you have a high initial cost, but it pays out exponentially over time. Sure you still have software costs, repairs, retrofits, and all that goes into maintaining your typically modern assembly line, but you don’t have to worry about your robots suing you for sexual harassment or wrongful termination. You don’t have to worry about busting unions or hazardous working conditions. You can fire your entire HR and payroll departments, too, which is even better for the bottom line.
Because it’s so financially appealing to so many industries to cut out human labor, I consider it an inevitability. The rich will continue to do what’s best for themselves and they don’t really care if the rest of us all die off from starvation or war.
Now, that’s not to say that it will all happen over night. Over the next half century it will likely be as you say where jobs just get more and more concentrated as they squeeze every dollar they can from each individual employee, but if you look far enough into the future we will all become unemployable. And when horses became unemployable, we didn’t set aside 100 acres for them to live their best lives in. We made glue.