"But this was merely a symbolic measure."
That sounds like you're refusing to give agency to an African woman judge. Are you sure that those are quite the right words?
Objectively, it was with Bensouda as prosecutor that the Palestine, Iraq and Afghanistan cases each progressed significantly (each in different ways).
Bringing the annual ICC budget [3] up to 1500 MEUR/year (factor of ten higher) would be cheap compared to the benefits: lawyers aren't cheap.