If we are purely speaking about security: Maps Go is "just" a PWA for Google Maps, in the end. Not only does it benefit from the traditional app sandbox, but it also benefits from the Chromium sandbox provided and enhanced by Vanadium.
Privacy-wise, that is more or less the same, as you're using the same service which may or may not collect usage data. Read the privacy policy and configure your Google account accordingly. Note that in both cases they can't collect sensitive data from your phone unless you grant them explicit permissions to do so.