I do something similar but with apple notes. Still simple but I get a bit of formatting and some checkboxes, tags and decent search. I can also create reminders that link back to highlighted parts of a note.
I have one exception: any 1:1 meeting with a person gets its own note and those go in a specific folder. One note per person and a bullet list under a date, with talking points. I also use this ahead of meetings; when I suddenly think of something I need to discuss with someone, I add it to their note. Then when I meet them, it's part of my agenda.
It's also searcheable so if I need to refresh my memory about an older discussion, whether it took place and when, it's a few keywords away.
My big complaint is that there isn't a decent Windows client. I sometimes will use the web version, but it's maddening because some of the keystrokes for things like word left or word right (ctrl-arrow) don't work.