Google Maps no longer shows user reviews of locations if you’re not logged in. It just shows the star rating. Probably for the same reason that Google Maps is not on its own domain, but the main google.com one: user tracking using google.com cookies.
It’s not perfect, but check out Organic Maps. It can work completely offline and is available on F-Droid.
CoMaps is a fork and continuation of the development which was stalled under Organic Maps.
Oh, neat.