If it does webdav, it automatically does passwords. My password manager has otp anyway. Calendar's important, but I'm pretty sure that it (and contacts) are also just webdav.
Notes though... ouch. I can't find anything for that, there's no decent Notes client that does webdav natively.
Obsidian looks interesting, I will have to see if I can get the plugin installed and tested. At one point the guy writing Notebooks did webdav, but Apple yanked the rug out from under him so that webdav no longer worked well and he just decided it was no longer a feature. And my notes have been a mess for years afterward. Joplin looked like it would be a good replacement, but it spams up the md files, so that if you ever switch away from it you'd spend months cleaning them up. So basically I've just been using an open Sublime window and syncing by hand... no fun.
I don’t use Joplin for this reason. I just want a folder of markdown files. It was mildly difficult to escape from even with the export features.
I did script the cleanup. Title field to filename, then remove the header completely. Or something like that.
Had another script that would take the date (which happened to be my filenames) and commit the file into a git repo pretending it was committed that day too. Dear diary style.
Quick and dirty but it did what I needed it to do.
I've been using Enpass for years. It's webdav functionality is sufficient, and it's available on every platform except my kids' Xbox (wish they built one for that, some passwords I have to keep short because they need them for the games).
It's not perfect, last year or so they keep trying to shove some ads into it, but nothing too obnoxious yet. And if you have any spaces in your webdav path where it saves the passwords, takes a little thought to work through.
Notes though... ouch. I can't find anything for that, there's no decent Notes client that does webdav natively.