Best experience I had with GraphQL was a B2B app where we had a fair amount of users, as well as the "backoffice" app also powered by GraphQL. Bad users we could just ban (the user base were great folks but could barely operate a computer, so it was fine).

Backend was with Absinthe+Elixir, so it was great (if I had to do it again today I would instead use Liveview, this was in 2017 where I had to retrofit a React app into something useable).

Public user facing is a different story, the last major one I saw was Tableau, though they are also business facing where they can just ban bad users. Github also has deprecated their GraphQL endpoints[0].

[0] https://github.blog/changelog/2022-08-18-deprecation-notice-...