For journaling I use the same directory structure but it is also a Hugo site so it can be simply turned into a blog.
I have also other categories in my system (notes which serve as blog articles; people which is my personal CRM where I also maintain my genealogy tree data; songs where I collect my favourite songs with chords and lyrics; music where I maintain my compositions; books I've read with reviews and scores etc.).
Hugo supports YAML preambules so you can add whatever metadata you wish to your files. Everything is in Git. Content is in Markdown.
It's a matter of a one-line command to get my weight stats or the last time I met someone or how many books I've read last year. I don't need to know these but it's easy to get that.
I have some bash scripts/aliases, e.g. to write a journal entry I use command `j` which will open four last days in vertical windows in Vim (and create the missing files if necessary and commit the changes then).
To seach any file inside the system I use fzf. You can simply use grep and other tools to navigate and work with the system. The public part is published by building the site and copying the data to my server. A matter of a few key strokes.
I guess it's time to describe it in more detail on my website.