https://techcrunch.com/2019/05/07/incognito-mode-comes-to-google-maps/

Being able to browse the web without leaving the usual local traces is a valuable tool for a lot of reasons, and now you can do the same thing in Google Maps. Incognito mode, announced today at Google I/O, prevents any movements or searches in Maps from being linked to your account or stored locally.

There are lots of reasons people might want to limit what their phone and Google account store when it comes to locations they look up or visit.