That system of vector maps is in popular use atleast since the 1970s, so when Google maps started, they could just collect existing gis (geographic information systems) maps. I wasn't born yet, but I expect that countries/companies started digitizing their old maps in the 1970s and 1980s and that paper prints after that were based on those digital versions. And countries without good maps to start from (too large/remote/administratively weak), probably started their digital mapping projects based on aerial photos. And when Papua New Guinea finally starts with a digital mapping project, they can start straight away from satellite photos :)

[–] [email protected] 7 points 5 days ago

I assume they take digital maps when possible. Most countries will have digital maps of their territories, be it for military use or research or other. And many companies do to. Digital car navigation existed before google maps and logistics companies for sure had digital maps as well.

For some parts I am pretty sure they just scan paper maps and convert it by hand.

Of course all of that is some sort of "maping". My previous comment was slightly clickbaity. But the process is still, Maps first, satellite later and not the other way round.