That's right, the ability to change just toolbar icon sizes like this was removed. It was an intentional change, as per the discussion at https://invent.kde.org/plasma/plasma-desktop/-/issues/58, which I'll assume you already read.

I'd recommend using screen scaling instead.

Yes, I know. The bug is about the default icon size for 100%. It is currently hard-coded to 22px (if I understand the topic) but which could optimally be configured to something more correct.

I'm not saying I want the icon sizes config back. I say it would be nice if the 100% default size could be changed. Changing the scaling is not an option in my specific case (something to do with hinted font rendering, which I am the last to use in the universe).

22px is the correct size; that's the intended default toolbar icon size.

But the thing is, I can adjust the icon size in any other toolbar per application (like dolphin's) as explained by the mentioned issue and I don't mind doing. I also don't think 22px is wrong per se (I'm just someone who thinks 16 is more appropriate). I just want to point out the choice is missing in the file dialog.

I'm in favor of removing the per-toolbar icon size customizability in those places too! Ultimately this is a design decision, and letting users customize it is asking users to be designers. If they want to, the right place is in the KDE Visual Design Group, so that *everyone* can benefit from their expertise and wisdom.

Personally, I actually agree with you that 16px is a more appropriate icon size for ToolButtons, and I even formally proposed changing it globally a few months ago. I can restart work on that.

I've been thinking about this and believe it or not, I'm passionate about it. Not because I think I'm right but because kde/plasma used to be the desktop that gave me the feeling I was in control, and let's be honest, the way things look is quite reminding of the feeling not being in control (and believe me when I say desktop scaling can not solve the problem for me).

So, the challenge seems to be one hard-coded default (but I might be wrong about that?). And the team wants to remove all (user facing) possibilities to change that setting. What if we created a "hidden" config setting that defaults to anything the team wants, that, when applied can override this hard-coded default? Read once, apply and forget.

It would prevent ignorant users of accidentally changing something that's not supposed to be changed, but would give power users a way to override one default without having to recompile the whole plasma desktop for their own use?

Hidden config-file-only settings bit-rot because they end up with only one or two users in the wild.

Thing is... why not change the position of the OK and cancel buttons too? How about moving the sidebar over to the right? Maybe remove some of the icons from that toolbar while we're at it?

The problem with "customizability" as a virtue in and of itself is that it leads to the conclusion that everything should be customizable, and this is infeasible as it transforms every user into a potential GUI designer of their own system. While this may seem like a potential good thing, it reduced KDE's actual GUI designers' flexibility to zero and makes it impossible to ever improve the UI, which ultimately hurts everyone not interested in doing extensive customization, which is most people.

We offer customizability where we deem it relevant, but we do not and never have supported it as a virtue in and of itself.

Blegh, I'm a dummy, we already have a bug report open for this: Bug 137837. Old one. I doubt anything happens there anytime soon, for the reasons I mentioned. But still, for correctness's sake, marking this as a duplicate of it.

*** This bug has been marked as a duplicate of bug 137837 ***