It’s not perfect - Markdown, or at least code blocks, would be nice, and tags (I think those are coming in the next OS release), but in terms of ease-of-use, I haven’t found anything close.
But I got irritated with Apple Notes. It lacks Markdown support. It auto-converts my note from plaintext to rich text anytime I start numbering, bulleting, or pasting, without a way to convert the note back to plaintext. Lastly, my notes had no structure or hierarchy. They were simply sorted by last-modified date.
So this month I researched note-taking apps having (1) Markdown support, and (2) support for syncing my data to Fastmail. Because again, I don't want to be locked into Apple. I settled on 1Writer[2]. It syncs to WebDAV endpoints, which Fastmail offers. My notes are now files, and I can organize them into folders, all within 1Writer.
For now, I love it. Markdown support is great, including highlighting in edit mode, and I don't miss anything from Apple Notes.
Go, plain text and open standards!
1: https://www.fastmail.com/help/notes/usage.html 2: https://1writerapp.com
On that note (no put intended), I’d expect iOS 16 Notes to support markdown now that SwiftUI and UIKit in iOS 15 now have native markdown support.
Happy to share the access and get feedback.
So a word of caution for other Notes users - Notes has its advantages, but if you ever end up with a large number of notes and you want to copy them outside of the Apple ecosystem, it will probably not be straightforward.
[1] - https://simplenote.com/