Joplin stores its files inside a database. Obsidian stores all notes as individual plaintext Markdown files.
In the first instance, that's clearly more future-proof and robust - your notes are immediately available in any application without a layer of abstraction. You can't have a single file corrupt and destroy all your notes.
I vastly prefer it for that reason. I want to know these notes are still going to work fine in 10 years, and be easily accessible.
I bought the aluminium and loved it so much I upgraded to the titanium. No regrets, although I can't say there's much difference except for the weight feels better.
I haven't used any other safety razors, but I can't imagine how anything could be better. It's so good I can shave with just cold water (no shaving cream) and it still comes out perfect.