In the future it might not be though. Developing countries are getting richer and they have growing populations. Britain's population isn't growing that much. Even public opinion within Britain may one day favour reparations, let alone outside of Britain.
A large part of the British population would like to do something as well.
Issue it, they know anything close to replacing the harm would bankrupt citizens who had nothing to do with the events.
When you think of the cost of paying back slave owners. As evil as the whole idea seems to us in this time. The cost placed our nation into debt until 2015. And that was a debt that basically built our economy. Seriously, few recognise this, but the UK benefited way more from paying off slave owners then from slavery or any other event in UK history. But still left descendents who never participated in slavery and were non-existent during those choices. Paying off debts for 182 years.
Reparations that do not actually leave the UK would be meaningless. So the request translates to people born 200 years after the actions with a debt that will only remove investment from the nation, harming future children who did not exist at the time.
Unfortunately, even those who want to do something find it hard to argue what.
Until the reparations debate can move towards a suggestion that helps all nations. It will be hard, no mater how powerful ex slave nations become. In fact, if your predictions are correct (and I agree they likely are) Move power in the southern nations will result in less ability for the north to make effective payments of any kind.
The conversation is needed. And has been since at east 1833. But without a time machine, that conversation is going to need to be more about building an equal honest future than repairing the past.
I think I heard on the radio the other day someone saying that reparations should be less about handing cash to descendants of slaves, and more about investing in descendants of slaves, which I guess would mean ensuring that those descendants have an equal access to education and job opportunities, and maybe other adjustments. Whether that's a good idea, I guess society would have to decide, but I thought it was interesting.