https://GitHub.com/samsquire/ideas https://GitHub.com/samsquire/ideas2 https://GitHub.com/samsquire/ideas3 https://GitHub.com/samsquire/ideas4 https://GitHub.com/samsquire/startups
I create a new markdown heading for each entry and write.
It's searchable and the data is easy to synchronize, backup and use and the solution shall last for multiple decades maybe even longer.
It's also indexed by Google.
I'm still tweaking my first journal that I created in 2013.
At one point I tried to love Emacs and I am yet to use org mode. I actually use the GitHub interface mostly to update my journal. And before that vim and lately IntelliJ which includes preview features.
I would recommend if you want to write notes or create an external mind to improve your thinking just write. The tool you use doesn't really matter. It's the quality and reward from writing and rereading what you wrote.