I can only comment on why I don’t want everything scaled - or rather why I want to leave my display scaled to 1.0 and have my fonts rendered at the hardware DPI of the physical display.
I want to use a variety of photographic tools and not all are scaling aware (I did post an example screen grab in another thread). I also want browsers and any other tools to show the image at true 100% so they can be compared with the same image in these photographic tools.
If I set the scale to 1.0 this works fine, except for font sizes which is addressed by setting the font DPI to 162 to match the true DPI of the display. That’s how I work in X11. In wayland I’ve done the same thing, but not having the DPI setting, as described in the other thread, I have to manually set this up:
% cat /home/tumb1/.config/plasma-workspace/env/hidpi.sh
export QT_FONT_DPI=162
(Except that window title-bars don’t see to obey QT_FONT_DPI and have to be set separately).
It was suggested that one day all photographic tools will fall into line, and all will show images unscaled. I don’t think that will be true for non-photographic tools, such as browsers. I also don’t consider waiting to be an acceptable strategy. It could take years, and old tools may never be fixed. It’s probably true that some tools will continue to run under Xwayland while others have moved onto Wayland. Staying scaled to 1.0 will hopefully avoid any potential issues with that mix.
I lack any deep understanding of the reason for taking away easy access to this choice. I think I read that setting the DPI might make some corner cases look wonky. I’m not seeing that with any of the tools I use. I don’t much care about the resulting aesthetics, just the usability.
Rather than moaning on too much, I should say thanks to all those who put effort into getting KDE to where it is today. It’s a remarkable effort, its usability and customizability are unparalleled.