For example some of my favorite Asian restaurants in the city are rated 3.5ish while Uber Eats is rated like 4.7. It leads me to believe a lot of people are rating Google Maps restaurants also based on service. One in particular
https://www.ubereats.com/ca/store/china-lan-lanzhou-beef-noo... (4.7)
https://goo.gl/maps/GnLmwJNRjBHP9UnN8 (3.9)
This place is awesome, and personally have experienced bad service but don't really care, so I do understand the Google Maps rating, but do find the whole rating system not helpful for me as I'm interested in good food and willing to accept bad service.