The results of a survey made by one of the GraphQL adopting companies asked the CTOs and lead developers of a variety of companies about:

- their experience with the implementation of GraphQL,

- expectations toward GraphQL,

- transition results.

They made a great job gathering data tech giants like Uber or Paypal, as well as small/medium teams ranging from 1 to 100+ software engineers. A short sum-up of the results here: https://blog.graphqleditor.com/why-companies-adopt-graphql/