wiki.js
It has a few UI editor options, but I can definitely recommend the WYSIWYG markdown editor

I used to do it that way too, but my wife is not technically inclined, so we settled on something with a web UI for editing.
There are a few areas where the wiki is marginally better for me, the main one being the ability to do quick edits from a smartphone.
I do really like the simple approach with a static site builder though

Your own wiki, and your own social media-type service

I post miscellaneous notes to my social media-type service, and save lists and more organised information (including recipes) to my wiki.

How about a utility for generating and/or handling QR codes?

EDIT: as there are tools to generate QR codes, how about a tool to handle them? Scan and present the option to open any associated links/display data