It's 'creaking' because it has been systematically been defunded by the Conservative Governments over the last 10 years or so. It is still doing a surprisingly good job considering it is quite overloaded due to low staff and funding numbers.
After Brexit, lookout for the US private industrial model being introduced by the Conservative Trade Deals which won't be anywhere near as effective.
NHS was gutted by Torys. "Creaking" gives a false sense of inherent model failure.