zim-desktop-wiki VS QOwnNotes

I'll slightly modify your argument; because Pure HTML does suck:

Why don't people make static sites with a simple "Markdown-or-Similar to HTML" converter, CSS, and vanilla JS...etc?

(This is what I do, btw -- http://zim-wiki.org + a template)

You should add Zim [1] to the "Personal Knowledge Management" section :)

[1] https://zim-wiki.org

https://meyerweb.com/eric/tools/s5/

And I just tweaked the CSS and added a bit of logic to included the possibility of one image per slide; as well as editing slides not with raw HTML but with https://zim-wiki.org (because that's what I'm really used to, I'm sure any Markdown thing would work just as well).

Absolutely; recently I realize I wish I'd never learned vim. I use too many other programs that are at least CUA-ish ( http://zim-wiki.org is the most important app I use ) and now I kind of want out. I haven't yet tried Modeless Vim, but that looks like my next experiment.

https://github.com/SebastianMuskalla/ModelessVim

It is so hard not to feel REALLY SMUG reading stuff like this, as someone who has run my own website as the working primary source for my college instruction for the past 15 years or so using https://zim-wiki.org. (before Markdown was much of a thing!)

It's borderline bizarre to have watched this method of doing things kind of die out, and then also come back in the form of "static site generators" -- which, frankly, are still way clunkier than this.

Write in Zim, export to html, rsync to site. Easy.

FWIW, I've been using http://zim-wiki.org for YEARS. (Sites a little messy and I need to clean it up, but it's extremely functional,) I host my college classes websites from it, to the point that I forced myself to learn the Canvas API, to just clone the page from this site to the front page of Canvas and change the links so they come back here.

jrm4.com

QOwnNotes: A plain-text file notepad with markdown support and todo list manager. Tech Stack: C++, Qt.

QOwnNotes

I use QownNotes myself. The notes are saved in Markdown format so that you can easily use them in other programs. An export function to HTML or PDF files is also available, if I'm not mistaken.

A lighter widget based solution that I know of is https://github.com/pbek/QOwnNotes/tree/main/src/libraries/qlitehtml No idea if that can work in QtQuick.

Personally, I use https://www.qownnotes.org. Notes are saved as Markdown files and are therefore easily readable. The rest of your requirements should be met by the tool as well.

QOwnNotes (note management)