I don’t think you have to go from here to planned economy straight away. There are capital gains taxes between the current level and 100% which might produce better outcomes.

People go into finance or adtech not because they have some innate drive towards making markets liquid, they go there mostly because it's more money -> higher quality of life. Moving more money into socially meaningful and beneficial fields (which is still far from a planned economy as the sibling comment noted) is not denying anyone agency.

A market economy is just as good if not better at denying "the agency to live their lives as they choose". Do you think the bum on the street or the poor family working paycheck to paycheck have more agency than someone with a decent job at a state owned enterprise and a social safety net? It's absurd.