It's very cheap (assuming car already has rotation sensors for ABS, and adding a software routine doesn't cost much either), and maintenance-free.

But there are drawbacks, too - it doesn't detect all tires deflating at the same rate. And also, ECU has to be very conservative to avoid false-positives, average a lot, pause comparison when turning, etc. As a result, you only get the tire pressure warning like 10 minutes later that dTPMS would've flagged it.

On the whole in that car (Golf R mk7) it did seem pretty switched on at noticing pressure loss from a slow leak i had after a tire replacement one time, which was handy because the tyres were pretty low profile that meant visual checks were utterly useless. It’d look perfectly fine at 10psi in a tire that should be at 34psi.

One other benefit of the ABS system is that when it goes wrong and the money light comes on, the user’s probably more likely to respond to a “brake service now!” Type message than a “TP-something or was it TS or oh i dont know but the car still seems to drive fine so…”

This is just a stupid tax on people unable to discern the difference between theory and practice and if anything life needs more of these taxes.