I have used deft on Emacs for years. It saves notes locally as text files (I use Markdown). I keep my notebook directory as a git repository, so that I can use my notes on any of my machines. Search and filtering is whole-text--no need to set tags. Not a problem until you have years of notes on a modest machine ;) That's as simple as it gets, and yet it has served me very well over the years. QOwnNotes is a non-Emacs solution that works in a very similar way, except that it does expect Markdown files and gives you HTML previews; in fact it can use my Deft directories unchanged.
Deft Mode: https://www.emacswiki.org/emacs/DeftMode QOwnNotes: https://www.qownnotes.org/