So you're getting both new reviewers (or travelers) who don't know it used to be better who still call it good, mixed with old reviews calling it good.
It's not even just a management change that causes this. This is when you almost wish Google maps would put your location history to use. It sees you visit the place frequently and thus if you stop visiting and leave a negative review it should weigh that review higher and give it more visibility. An old stale review or a review from someone who visited once I don't think should be as impactful or useful on the experience.
Overall I find discovering new places to be frustrating as reviews often seem useless. Usually I find the best method of discovering new places is still via word-of-mouth in person.
But how would that make Google more money, this quarter?
I could imagine an argument that, over a long enough time period, (re)gaining user trust would lead to an increase in ads revenue, but at best that long-term increase goes into the promo packet of the T9 leading "Geo/Commerce" or whatever the product area that contains Maps is these days.
The other option is using a bank api but seems too much friction..
The previous sentence makes sense. That is not the problem.
This is:
Change.
Read it through again and you'll get it.”
-- Douglas Adams, So Long, and Thanks for All the Fish
Any information repository eventually comes to face the problem that the phenomena it is describing is no longer the same, for intrinsic or extrinsic reasons.
A popular local restaurant came under new management and their food is now atrocious. We actually threw their food in the garbage after getting takeout there a month ago.
Meanwhile, tourists are still leaving thousands of rave reviews on their google maps page. Noticeably, you will see one or two bad reviews every 50 reviews or so, where a person comments about their confusion about the restaurants score.