Joplin is open source, syncing setup between devices is one login to Dropbox, works for free, with native apps on Windows/OSX/Linux/iOS/Android. It has a bunch of plugins too. If you just need markdown files with syncing, use it rather than paying for Obsidian sync.
The 2GB free quota on Dropbox is plenty enough for text (and some screenshots). Or you could self-host obviously. Git while lovely for source code is a hassle for notes.
It saves to sqlite though, not markdown files you can edit on disk.
I stopped using Dropbox, but this is pleasant news that they have this much space.
I use git and it works well and gives me security my notes will not dissapear.
On mobile used to be more difficult so I used specialized app before but now Obsidian git works well enough.
It can be better but overall it works well enough for me. I would dictate things to my phone in daily note and later process those more in desktop.