I think your opinion that robots can replace human's workplace is great. But there are some unproper reasons in your essay.

You said when robots replace people's jobs, the cost of producing something is significantly reduced compared to when people work.

But, if robots replacing human's workplace are released to people, it will be very popular among them. So, price of the robots will be expensive as time goes and it won't be easy for company needing a lot of robots to buy them. Also, fee of administrating many robots will not be cheap.  Therefore, it is not necesarily to  reduce the cost when making production.