With Indirect TPMS, also known as Tire Pressure Loss Indicator, it uses the ABS sensors to determine each wheel's rotational speed.
If one of them is off in comparison to the others, it will set of the TPMS alarm. Usually this equates to 4 psi or more.
It can only do this comparison when the car is moving.
If the pressures r the same, but the tires r worn out differently, it will rotate at a different speed, and may trigger the TPMS.
If the brakes r binding, it will rotate at a different speed, and may trigger the TPMS.
If one of the wheel bearings is worn, it will rotate at a different speed, and may trigger the TPMS.
Hence there r multiple reasons for the TPMS to b upset.
With direct TPMS, which is not available on the Superb, it doesn't rely on the ABS wheel sensors. Instead it has 4x sensors, one in each wheel, and a TPMS module (receiver). It measures the actual tire pressure, which gets displayed on screen.
As @MartiniB indicated, there is the option to fit an aftermarket TPMS system, to monitor ur tire pressure live.
in my case - I retrofitted the VW/Skoda TPMS system.