For example I think GitLabs CI is the worst on the market but if you integrate another CI you don't have a means to feedback information into Gitlab.
You can do almost everything with the Gitlab API so I'm curious what issue you had.
I'm also not sure why "Gitlab CI is the worst on the market"? I really like in particular that I can have my own gitlab-runner on any machine.
In term of privacy this is pretty bad though. From the upvotes/downvotes activity you can very easily build a whole graph of stuff you like/dislike. For advertisers that's juicy data.