That makes a lot of sense.
TBH, I would go with a cloud service in your situation. You’re using icloud now and if you can avoid changing away from it you should. Theres a snap (ugh) that purports to do this natively, but even on a nearly 15 year old thinkpad I can spare the clock cycles and memory to bring osx up in a vm and do it normal style.
I say a service, and you said you’re interested in syncthing (which is very useful) but I’d stick with icloud or something more like it.
I was in a disaster we never thought would happen. My self hosted server was rendered inoperable by it. My offsite backup on the other side of the county was completely destroyed. If it weren’t for cloud backups I’d have lost data. Connectivity was sparse and if I had been privacy focused in the immediate hours I would have recognized then that it was entirely provided by spare bits of dubious infrastructure brought in by the government.
Cloud services like bitwarden and icloud saved by butt. They were prepared for this unimaginable situation to a degree I couldnt have been. When I had a dead phone battery and no laptop, both were able to be accessed securely on other people’s computers and public terminals.
I wouldn’t worry too much about the privacy aspect. Once you have ADP on in iCloud you’re safe from lawful orders and interception is handled by transport encryption like tls, wireguard or whatever. Your pc is a concern but open source versus closed source isn’t the security panacea people make it out to be.
An open source package called winring0 -yes really, it says it in the name- that was abandoned by its developer 15 years or so ago for being a terrible security nightmare was found recently to be in lots of windows rgb drivers shipped by manufacturers today.
That is to say, you can’t really protect yourself from manufacturer and maintainer error or maliciousness. You choose to trust them and have to accept what you get until it’s too spicy and the whole system needs to be ripped out and replaced.
What I would do for privacy is audit my behavior and set up key (or password!) rotation. It’s easy to make sure your secrets are isolated from each other and regularly changed.
If you’re really concerned then make sure you have whole disk encryption (and understand how to recover data from the encrypted disk when the computer it’s attached to fails!). If that doesn’t feel like enough, store your db and any flat files encrypted as well.
In short, don’t change your working system. Change the way you interact with that system to meet your new needs.
I clicked the little rainbow star to see what people not federated with my instance are saying.
You’re getting a ton of bad input and inaccurate or irrelevant information.
Do not rely on community consensus to establish proper use guidelines.
As another person stated: signal chats don’t go to icloud. You have nothing in the slightest to worry about on that front.
People are bringing up prism and push notifications. It is mandatory for companies operating in the us to comply with us government prism spying requirements. Turn on ADP. Read past the slide presented as supposedly damning evidence against one or another company if you want to understand better law enforcements processes over a decade ago. Push notifications are plaintext and represent cause in some cases. This is not unique to apple. If you think you are one of those people, turn them off.
Turn on lockdown mode. Update your phone. Turn on automatic updates. The ways people physically and remotely compromise ios are often stopped by those three things.
If you don’t already, restart your phone daily. It puts the phone in a restricted state called before first unlock that requires that non resident programs have to reload and in almost all cases have to reestablish themselves to the host os.
If you’re worried about your signal chats getting recorded, turn on the disappearing feature. The other person is the weakest link, not the technology. Do contact verification. Assume your chats are infiltrated and talk to people about illegal stuff in person like the scions of American industry do. This is not unique to apple.
Be safe out there.