What if those generations are not "lost" but are spent? We took humans, we extracted every bit of work from them, we got a lot of work done and a lot of empty

What if those generations are not "lost" but are spent? We took humans, we extracted every bit of work from them, we got a lot of work done and a lot of empty shells for people. What if with each generation it's an downward spiral? Because it certainly looks so.