I agree with everything you said except for this:

Plus, DotNet is almost trivially cross-platform these days and almost ridiculously easy to develop with… for something like an install script you really don’t have an excuse to not hit all three platforms anymore.

But so is Java. Or Kotlin. Or Rust. Or Python. Hell, even JavaScript is acceptable for a simple GUI program that’s meant to be run once to install the real program.

And those are open source and don’t have Microsoft telemetry in the build tools AND IN THE RUNTIME!!! So you now have to taint your Linux or Mac system by installing the JVM we have at home.

How’s signal compared to Element?

Also, is there a secure way to directly send messages to someone else’s phone without the message having to be stored on a central server? As in they’re only stored on the recipient device. Is that even possible with how the internet works and how packets are routed between networks? Even if the server has no way of decrypting messages by default, just having the encrypted messages stored there is a liability because your encryption keys can easily get leaked by malware running on your device, phishing, etc.

I already have a pixel. Is it just as easy as installing Lineage OS on the phone?