I can use my phone to CPU mine with https://github.com/XMRig-for-Android/xmrig-for-android albeit at a very low hashrate. IDK about GPU mining though, seems like that could be more useful. But if you root your android device you can pretty much install anything you would on a linux system, with exceptions.

Also, I don't see why you couldn't just distribute a defi app on android as an APK, including tornado cash. I don't really know if trading on leverage is a critical part of using cryptocurrency, but I don't really see how you would be prevented from doing that on mobile unless your CEX distributes a different desktop app.

Crypto is not heavily censored in the US. I mean maybe, but it depends on what state you live in. Also, you can't legally mix coins as a service like tornado cash or coinjoin server, as that constitutes money laundering.