The administrative problem with general taxation funding is not merely theoretical. Follow the money. A British government collects taxes from all its citizens, including several million people of Caribbean heritage. It sends a portion of that revenue to, say, the Jamaican government as a reparations payment. The Jamaican government uses some of it to fund programmes that it says benefit the descendants of enslaved people. Some of those descendants live in Jamaica. Others live in Britain and contributed to the original payment.
The money has gone from British Caribbean taxpayers, via the British government, to the Jamaican government, to be spent by that government on programmes that may or may not reach the intended beneficiaries. At each stage, administrative costs are incurred and opportunities for diversion arise. The person whose ancestor was enslaved, whether they live in Jamaica or Britain, receives whatever the Jamaican government chooses to give them from a payment funded partly by their own taxes. This is not what justice looks like.
