Is there is a “Yelp for SaaS”? (Or replace SaaS with any of “cloud”, “platform”, etc)

I hypothesize that lots of time and effort is being duplicated by teams migrating an integration and wasting a lot of time before realizing a service has severe drawbacks. My most recent project was to integrate AWS Cognito (authentication solution) a few years ago before aspects of it were very immature for customer-facing purposes.

It’s easy to find lots of PR / sales material that focuses on the positive side of platforms (the 5 star reviews). I’m more interested in collecting the 1-3 star reviews as they can help identify likely pitfalls before investing too much hope in one implementation.