I'm not going to comment on the potential technological unemployment part, but we are certainly not massively overpopulated. This is a common misconception. You cannot just look at the size of a population to determine overpopulation.

We are actually massively underpopulated. We have too many boomers and stagnant population growth, due to low birthrates in the newer generation. In the last 50+ years, the only countries to really grow are 3rd world countries.

We are already seeing the ramifications of this, by lacking literally millions of employees in the work force. Our population is "big", but its severly right skewed towards elderly people who cannot work and also need a lot of care and help during the day, combined with not enough new kids being born.

You have to look at it more like a funnel where a certain amount of input flow has to compensate the output flow. Right now we are looking at a population who previously had a massive input, but no longer has enough to even sustain the population at its current size.

We are going to see massive work force problems in the coming decades, since we will have so few new people entering the work force, due to generations of stagnant birth rates.