OneSignal is not optimal, because of its data sales and because of the buggy integration. But its the best we have. Hopefully an integration with a better PUSH solution will come along. that will allow us to pay for PUSH.
Yep, I have other mobile apps that use it and we make it well known that data is being trafficked. I think it's always been the case. Having said that not many affordable alternatives, firebase is still sketchy for push and the other more indie players are lacking in tooling and adoption from what I've read. I believe OS offers a paid private alternative.