Set Google maps as default

The "Look Up" functionality is provided by the operating system (macOS from Apple), not from Google Chrome. I doubt that Apple would want to use a Google service in their OS. Also, there is no Google Maps application for macOS, therefore further reducing the chance of looking it up in Google instead of Apple maps.

PS

If you wanted to look an address up in Google Maps, you could probably make an Automator "service" that would take the selected text, and add it to a GMaps URL.

Just to add, if you are in Chrome, highlighting an address and choosing Search for instead of look up opens the tab with a Google Map on top which you can click to open the Google Maps page.

I see. You meant "Look Up" not search. No, it's not possible to switch.

Can you elaborate? If I highlight an address in Chrome and choose search from the contextual menu it opens a new tab, not Apple Maps.