This writer really likes “devolved” for some obscure reason. Must a very involved and revolved subject.
Devolution is/was a big thing in the UK.
Until 1997 the UK was one of the most centralized states in the world - probably the most along with France. Whitehall would define even local council matters.
Tony Blair devolved i.e. gave the constituent nations of Scotland, Wales and Northern ireland more rights to govern themselves.
They still have less powers than US states, but better than before 1997