It already took a mountain of resisting the network effect to get at least some half of my friends to chat with me on Signal. The chances to get them to move to something more obscure, that has any additional friction is low and the effort in convincing them will be high. That's not to say I won't try, but man I hope it doesn't come to that.
Tesla...certainly isn't top of mind when I think about makers of technology products that permit true ownership of the hardware / respect their users' privacy.
A phone made by a car manufacturer that abuses access to car cameras to spy on customers in their homes and share videos of them being naked? You can't even pay me to make me use such crap.
Unfortunately, "reasonable" generally means "can do the things typically done with smartphones these days", which include things like banking, media streaming, and civic stuff - things mediated by the very systems whose vendors aren't just embracing remote attestation, but actually driving its proliferation.
For better or worse[0], this is not a technical problem - it's a social/political one. Technology created it, by making remote attestation possible - but the actual problem is with why companies want to use it.
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[0] - Definitely worse. Technical problems are easy.
I don't care about this kind of private communication. I care about automating and debullshittifying my life, which includes stuff like banking and civics.
I didn't learn to program computers so I could use it to shitpost more privately. I learned it so I can make machines deal with things for me the way I want them to.
Move now to alternatives. If you must use Android, GrapheneOS with Sandboxed Play Services.