In case you hadn't noticed, within the last 20 years the UK made an enormous constitutional change by leaving the EU.

That is the one change, and it hasn't resulted in the thing people actually were voting for (but couldn't): less immigration. Because the state says we must just import 750k people a year, so that's that.

Made by the people rather than the politicians- the mainline politicians all thought it would/wanted it to fail- they just thought they’d get a boost from catering to a disaffected minority.

But no government has reversed that step.