The truth here depends on the definition of "useless".
Automotive GPS systems existed pre-2000. So did dead-reckoning systems. Did people use them at the time? Some did. It was an amazing technology compared to the alternative, which was manually navigating a paper map.
But you'd often get errors large enough (50m avg) that it wouldn't accurately identify your location on roads close enough to provide accurate instructions. If you gave any of that tech to someone today to use, they'd think it was broken.
As example the TravelPilot IDS/1989 first prototype from 1983 (see [1] if you want a picture)
IIRC the system used a compass, a shunt for the heating wire from the rear window (it would alter the compass because of its magnetic field) and two wheel sensors measuring the rotation of the wheels.
Automotive GPS systems existed pre-2000. So did dead-reckoning systems. Did people use them at the time? Some did. It was an amazing technology compared to the alternative, which was manually navigating a paper map.
But you'd often get errors large enough (50m avg) that it wouldn't accurately identify your location on roads close enough to provide accurate instructions. If you gave any of that tech to someone today to use, they'd think it was broken.