Yes and it clearly states this in the manual.

TPMS is not a substitute for regular checks and maintenance. It only allerts when pressure falls by a certain percentage, in my BMW that equated to about 10 psi. By spotting the pressure drop before TPMS allerts you there is a greater chance of getting the tyre repaired.

An this applies to all brands and not just BMW.

Only fools rely on idiot lights.

Agreed. The system will probably not detect a slow, gradual loss of pressure.