By DE, I'm mostly talking about having a cohesive graphical shell, not the random apps that comes pre-installed (who cares about those?).

The login manager, lock screen, taskbar, notification daemon, launcher, OSD, workspace overview, etc. In WMs (or WM-like compositors), you either have to cobble all of this together yourself or just give up and convince yourself that you're a minimalist.

Doing this kind of stuff was fun for a while, but these days I'm starting to crave for something actually good and polished.

FWIW i do like and use Falkon (KDE's browser) often these days as it is based QtWebEngine (Chromium in Qt) but has a simple Qt-based interface. I still use Firefox as my main browser but when i need to open a completely separate browser (sometimes sites do like my Firefox configuration - or i just want to test out something) i've found Falkon to be the best alternative.

Also Kate is better than Emacs as far as i'm concerned because it doesn't have its own weird UX and doesn't take reading a tutorial to figure out how to have a sidebar with a file browser in it :-P (i've long figure out how that is done on Emacs and use it occasionally because of custom language support elisp i wrote ages ago and don't want to bother rewriting but these days 99% of my plain text editing needs are covered by Kate).

(also FWIW i'm not using KDE/Plasma as my DE, in fact i'm using Window Maker instead of a DE at all, i just like some of KDE's utilities)

I'm using KDE and I have neither Konqueror nor Kate installed. Those are very much optional, I don't consider them part of the DE.