Org mode

there's no comparison: org-mode is the best for note-taking, personal task management, literate programming, etc.
there's a lot of Emacs packages for adding functionality to org-mode, like creating blogs with hugo/ox-hugo, doing your math and previewing it with latex integration, researching with org-roam, and the list goes on.

edit: currently the most problematic thing with org-mode is mobile support. On Android there's orgzly, but it's essentially only useful for task management. Now there's organice, which is a web app that's trying to solve this so you can edit org-mode files through your web browser either mobile or desktop.

Very customizable, wholly private with no web dependency.