There are various reasons why this happens. It's possible the location accuracy option is disabled, you're using an older version of the app, or you don't have proper access to the internet. The Google Maps app itself may have issues, too. Cache files and other app data can sometimes cause various issues with the app.

Why is Google Maps so unstable?

In that case, the reason could be that the Android device doesn't meet the minimum requirements for the regular Google Maps app to work properly. In that case, you can always try Google Maps Go, a lighter version of the app. This app is designed to run more smoothly on devices that have more limited memory.

What happened to Google Maps?

Apple replaced Google Maps with their own a few months ago, and it'll only be a matter of time. There's an app called Live Street View as an alternative. Try the free one until Google Maps returns. Another option is to use the Web version of Google Maps for street view.