Let alone software, there is an infinite amount of ways how stuff can be better and more efficient. The same goes for engineering, as long as stuff costs more than the materials it takes to produce them. Let alone new fields like material science (graphene) or space exploration.
The demand for those jobs will grow even more to make this robot future happen.
The only thing that needs to change is education in those fields. Why can't work the rest of our population in those areas? Just use tools like capital gains tax (the value those robots produce) and direct those funds into education. If you say that's impossible, in theory a person with average intelligence can learn those things by himself with a single computer.
Tell me where the big flaw is here?