Serious Question: what would happen if a place aimed to maximize 1) Average median annual income, and 2) Socioeconomic mobility?

Afaik, this most closely resembles Nordic nations such as Norway and perhaps the US before Nixon. And while no system is perfect, it generally aims to offer a 'A high-functioning, education-driven, market economy with strong labor institutions and a moderate welfare state'.

I don't really understand the arguments against pursuing and refining this goal; is it not a rational objective to pursue?