My primary requirement for personal note taking is self hosting. That's the only thing that assures me that my years of notes will be available when I wake up every morning.
(And if I don't wake up one morning, I doubt I'll miss the availability of my notes)
I am curious what kind of information do you have in your notes that you keep them around for years.
Not trying to mock or anything but I am wondering if I too would benefit from such a thing. Most of my notes are ephemeral and I delete them soon (within weeks at most).
I write lots of thoughts, plans, logs of activity, to do lists that stretch back, literally, years (and yes, there's a limit to the practicality of that, but they can also be culled, bit it's also just text, so it's not like it's taking up precious storage space).
I always tag each 'note' so it's mostly findable down the track.
I use it to document the backup process of my homelab, and so those notes grow and change over a relatively large period of time. Also document various docker-compose scripts and straight docker create scripts for the various services running on my network, and they get tweaked with some regularity (updating PiHole and Jellyfin instances etc.)
Thinking about your question, "notes" probably is an understatement of how I use it. "Documentation" is probably a more accurate description. Something like my "digital life wiki".
FYI I use noteself, self-hosted using a couchdb instance. Noteself is an extension of tiddlywiki with pouchdb built in as a local in-browser data store (which, with the setup I use syncs with a couchdb instance). I've used it for a number of years.
StandardNotes makes daily encrypted exports to your Google drive, mailbox, and others.
That's not self hosted but it's texts files so... Good enough for me.
The self-hosted-ness also provides the ability for me to access my notes, password protected as well, from any computer with a browser. If I'm on my work computer and remember an appointment or an important task, I can load it up, add the task, and it's there on any other device I access the notes through.
For a while now I've been aiming for a setup with minimal dependence on any specific device. The device is throwaway whilst the service is consistent. There are obvious limits to this, however.
(It feels like something like Nix would be perfect for scripting the device specific setup for accessing the services, I just haven't had the time or motivation to get into that)
(And if I don't wake up one morning, I doubt I'll miss the availability of my notes)