Oh that sucks, there's always going to be those who will say that it's the price you pay for using Github, but locally hosted VCS and CI/CD systems have issues as well.
External dependencies are always problem, but do you have the capacity and resources required to manage those dependencies internally? Most don't and will still get a better product/service by using an external service.
Perhaps "many" would have been better. If you only count companies that view themselves as IT companies then number of companies with self hosted/managed solution grows, but if you include everything then I'd guess that more than 50% don't run these services internally. If you're every small company with one or two developers that doubles as the IT staff then the numbers add up pretty quickly.
External dependencies are always problem, but do you have the capacity and resources required to manage those dependencies internally? Most don't and will still get a better product/service by using an external service.