“The one who will cure cancer will be a desired, wanted child. [with probability 99+%]”
Then don’t stop at your desire to pay for abortions. Let’s sterilize all of the blacks, latinos, and whites and keep only asians and jews. There are of higher IQ by statistical standards and would provide a much higher standard of living.
Then who would do the day-day work? The world is already ordered along these lines and, with the exception of certain policies, seems to be working pretty well.
Technology (medical, information, etc) and business is developed, financed and advanced by the most intelligent ie graduates of the world's top 25 universities. 2nd tier managers and distributors are employed to manage growing organizations and deliver goods & services. Manual labor provides actual assembly (unless robots are building robots) and service/maintenance. A criminal underclass exists to employ those in law enforcement.
Overall unemployment is under 5%. What would be achieved via eugenics?
I am not a collectivist - and I do not like collectivist coercion which would be necessary for your scheme. Voluntary abortions are about as far as one could go.