The theory is valid but too abstract to really point out where people lose something in return for what they've gained.

It's true that people can gain efficiency with specialization for example, but that's not necessarily a gain unless you define efficiency as the primary goal to be achieved.

This gained efficiency will then over time make this the most economical way to produce. This effectively harms everyone that hasn't adapted yet

It's just not an easy topic and claiming it is doesn't help whatsoever