Efficiency: The Logical Conclusion

I have a concern that at some point our increased efficiency, already evident in agriculture and manufacturing, will mean that there simply is not enough valuable work to occupy a majority of adult humans.

If the third world is eventually able to achieve full economic development, that will mean virtually the end of the subsistence farmer and laborer.

When, just to throw out a number, one tenth of the population is able to produce all the food, medicine and material goods necessary for the other nine tenths, exactly how do those other nine tenths justify their existence?

There is only so much "service" and "knowledge" work that needs to be done, and we're getting more efficient at doing it all the time.

The logical extension of the trends of technological achievement is that a large segment of the population will become productively superfluous.

There is no culture on earth that is prepared for that. There is no culture where one tenth of the population is prepared to productively support the superfluous nine-tenths. It's a recipe for civilizational catastrophe.