If they were just developing software that would be way too many, sure.

But if you count streetview car drivers trying to drive every street in the entire world every few years, people manually moderating crowdsourced contributions, people updating the map for all new construction worldwide, people working to maintain business listings for every business with a physical location (including those without much web presence), people dealing with adversaries who want to list their fake '24 hour emergency locksmith' all over every city, people parsing train and bus timetables in every city worldwide no matter how awful their websites are, an advertising sales team specifically targeting smaller businesses who are interested in local advertising...

Nokia Maps (I used to work there) when they acquired Navteq back in 2006 or so was something like 7000 people or so, most of them in Navteq. Navteq had employees and people in most countries in the world to be able to gather mapping data and work with local authorities. It's now called Here and they still have 9000 employees or so (in 2019 according to wikipedia). That's after years of decline and layoffs.

The Navteq acquisition is what prompted Google to create their own maps. They were licensing Teleatlas (now Tom Tom) and Navteq maps before that. Apple made the same move a few years later. I think Steve Jobs was still around. I bet Apple has a few thousand people working on this topic as well.

That's just what it takes to build and maintain a world map and assorted geospatial technologies, datasets, etc.