It’s worth remembering the original iPhone did not have GPS at all. It had google maps for calling up information like you would with map quest, but no turn by turn/live navigation
It had basic geolocation feature though so you could mostly see where you were on a map which was still very useful compared to flip phones
Cellular triangulation worked really well on the classic iPhone - if you were in a very crowded place. In more rural areas, you could be off by many kilometers. I’m not sure if they had Wi-Fi SSID location back then.
I remember Garmin and TomTom share price dropping when Google announced it was adding turn by turn navigation to Google Maps. It was an amazing time.