I spent lots of time with notion and obsidian and this is what I came to as well.
What I do now is have markdown files, and use the OS folder system for organising. I then use OneDrive for syncing - this works perfectly fine between MacOS and Windows, and for both I use Visual Studio Code for editing. For android I use an app called FolderSync to sync and TMarkor for editing.
Has been working perfectly for over a year now.