So either we stop having sex right now and let the population shrink

That is happening in first world nations, birth rates are declining.

Or we can decide to ship all foreign computers to their countries of origin, because they are the immigrants taking our jobs.

But then that still doesn't give a job back to someone here. If someone here is replaced by a computer/robot, and we ship that computer/robot overseas, that's no different than if we actually outsourced a persons job to overseas. Doesn't solve the problem at all, as it still doesn't keep the job here.

At least if it's here there are some jobs in repairing the computers/robots; engineers, repair techs, sales people, etc. Automation has created a job market all it's own with higher paying jobs albeit ones that take more experience and education. But yes it takes away from other markets like labor, clerical, and data entry. I work designing a web application that is essentially automating the loan foreclosure process for banks... I was in a meeting not long ago where my CTO told me that a new application we're working on is going to help a major well known bank in that they won't have to hire 1,500 people to do the work manually. I don't know why he told us that, as it's honestly kind of depressing. But I work in IT, part of what we do is automation and making it easier for less people to do more is kind of our thing. But it's the darkside of my job that I don't really enjoy thinking about.

Or, and this is a radical solution so bear with me, or we can decide that jobs aren't the most important thing in the whole wide world and find another metric for a successful society.

"New metrics" don't put food on the table and pay rent or mortgages for anyone. Things cost money, and until we have a one world government and one currency, things like trade, GDP/GNP, and the value of our currency play a major role in what our government can spend on it's people. We can't just print money and take care of everyone, it just can't work that way right now in this global economy. I'd be the first one to wish that wasn't the case, but it is.