I use Obsidian but I don't follow the whole "second brain" thing, I just organize my notes by directories. You can use Obsidian however you want and adapt to the way your actual brain works. The "second brain" thing doesn't work for everyone. Even taking digital notes doesn't work for everyone (for example, it looks like you prefer paper notes).

If you haven't tried Obsidian at all I think you should give it a shot and write notes without following any system in particular. If you've tried it and you still prefer paper notes and the occasional apple note, then perhaps Obsidian isn't necessary for the way you take and organize notes.