Signal set the industry standard for encryption and privacy, and it’s what I tend to point people towards. The one down-side is that it is still tied to your phone number, so solutions like Element/Matrix or XMPP with OMEMO might be a little better for some use cases. My wife, kids and I use Conversations(.)im for our intra-family chats and use Signal for talking to everybody else.
She straight up admitted that she was essentially a sock puppet CEO and would offer no friction to anything Musk wanted.
Not sure about what carrier you use or what device you use, but I’m on AT&T using a Pixel 6a with CalyxOS, which is just de-googled Android, and on Android if you accidentally swipe away an amber alert notification you can find it again by going to:
Settings -> Safety & emergency -> Wireless emergency alerts -> Emergency alert history
But your point still stands, governments and public institutions really need to stop relying on privately owned and operated social media platforms for posting stuff like this. If they want to use a social platform to publish alerts, they would be much better off standing up their own Mastodon instance that is “just” for those alerts. People could follow those accounts if they want, and those institutions wouldn’t be subject to the whims of overpaid unpredictable man children.
I’ve been running Debian stable for years now on everything. My laptop runs it, my home server runs it headless with no GUI installed, my gaming desktop runs it and even my kids run it without issue. If we need a newer version of some desktop app I just get the Flatpak. It’s pretty great and the good thing is that it’s predictable. Once it’s up and running I don’t have to worry about things breaking because of an update.
I have an external hard drive that I keep in the car. I bring it in once a month and sync it with the server. The data partition is encrypted so that even if it were to get stolen, the data itself is safe.
I’m using CalyxOS and it’s pre-installed as a system app, so this seems like something that’s being built in at the AOSP level of development.