One could argue that social economic systems, at scale, are functionally similar to a massive corporation operating on a flat environment. And you end up with a similar issue there. "Company" ambition doesn't really have a viable path forward, and so the optimal solution is to just coast by - and direct your ambition towards your own personal stuff. Or even set the ambition aside, and just enjoy life. At least until the consequences of everybody operating under a similar system of demotivation kicks in.