I quite like Obsidian too. Markdown note app that has desktop & mobile versions. You can create templates and have it so that a new note using a template is opened automatically when you open the app (e.g. for daily notes). It also supports a lot of different community created plugins.
I sync across android & linux via google drive for free, otherwise Obsidian also has a paid sync feature.
If you’ve used Anytype, can you share your experience? I have an account and I’d like to move over some of my Notion content, but haven’t had time to try it yet.
I started on a similar journey (escaping from Evernote rather than Nextcloud), and ended up on Silverbullet run at home and accessed over Tailscale. It is a bit of a different approach and has a small upfront learning time. I love having all my notes as reasonably plain markdown, so if I ever want to change my solution, my data's in an easily movable format - for example changing to Obsidian would not involve any import/export.
Are there certain features you've grown to rely on?
I use plaintext documents with markdown. There's a markdown editor for the web. Markor is an excellent Android app. Take your pick of a number of text editors with markdown.
Notesnook is not ready for self-hosting yet, but it’s up next on their roadmap. I’ve been trying it out in advance and it seems to work ok. The only issue I have with it is that it logs you out of the apps way too often.
Joplin via Dropbox (free account) is effortless and painless. I used to sync it via nextcloud and it always gave me issues. It has an iOS, Android, and Desktop app so why do you need Web Ui?
A webui can be extremely useful on, say, a work computer with strict install policies, or if you're borrowing someone else's machine and need to look something up (maybe you're fixing or installing something on someone else's computer and want your notes easily accessible).
There are other note apps that can sync with Nextcloud. I settled on Quillpad because of its checklist functionality, though admittedly it's not perfect.
Logseq can be launched as a desktop app and in a web browser and has both iOS and Android apps. Official sync is a paid feature but there are other options (e.g. Syncthing).
Memos might do the trick for you. There is a 3rd party android native app, but I found the PWA to be quite good. Markdown is stored in a single sqlite db file though, if that bugs you.
It is odd that there’s no web app for Joplin given that it’s written in TypeScript. It’s such a commonly requested feature, I wonder what the problem is.