I understand your point on it…..Parliament in making laws has to take account of precedent’s and long established common laws, if the Judiciary find government actions are unlawful in tabling legislation, then the government can’t be able to override that “separation of power”. It’s a long established scion of British common law which has been mostly adopted by the rest of the world.
checks and balances are designed to keep Parliament and the judiciary in its place.
It’s the main principle behind the separation of duties which defines democracy.
Again we can’t cherry pick based