Overseas colonies are expensive, when they can't be brutally exploited, and the UK doesn't have an expansive global empire to suck the resources from anymore.

It does look like a sticking point here was a strategically significant FOB, Diego Garcia, which will not be handed back over.

So the UK has to suffer another embarrassment that reminds them they're no longer a global superpower, but they also get to save some money, and retain access to an important strategic asset.

They might also get some good press for continuing decolonization, I can't speak to that, as I'm not sure how, or where, they might have felt any real political pressure over this.