I can (vaguely) remember a time when such a thing might genuinely have meant something. A handful of departments, a handful of ministers and a change could possibly have a fairly dramatic change in policy.
However, this is no longer the case for two reasons: firstly, there are so many ministers and secretaries and departments and sub-departments that shuffling the whole lot around is going to change nothing because no role carries any actual power; secondly, every single member of parliament, Tory, Labour or Lib Dem is nothing more than a troughing makeweight, none of them have a useful idea in their head or the stones to make them happen.
Quietly, possibly not even with malice aforethought, the power in the country has slipped from the elected politicians' grasp into the quiet, sleek hands of unelected civil servant mandarins. This is not a new thing, the more venerable among you will remember "Yes, Minister" which, even then, was more factual than fictional.
The personal prejudices of entirely unaccountable, anonymous apparatchiks define how we live our lives, while tribal warriors on all sides froth vacuously over people who are carefully placed as lightning rods to take the heat over decisions that are made by people far from the limelight.
Not one of the minister's ideas or plans will ever see the light of day unless the civil service think it's a good idea and even if they do, they will not happen while that person is "in charge" of that area.
But crucially, it doesn't matter who you vote for or how angry you are - you're shouting at the shop-window display. The clerks inside are the ones who decide what you're getting.