Degoogled Android on the phone, Linux on the desktop. These are the most free options we have right now, afaik. I'm on Degoogled Android and I don't need to worry about Google taking Amethyst out of the Play Store as I'd just download the apk or else get from Fdroid. That's pretty robust censorship resistance, especially compared to iOS.
Discussion
It's not perfect, but it's better. I hope to see a lot more open source alternatives appear, but they can only survive if users support them.
That requires people to stop being corporate fanboys and care more about freedom and functionality than a status symbol.