After testing many desktops it seems that, as of 2025, KDE seems to be the most complete, consistent and polished desktop experience available, at least in the "conservative paradigm" category (GNOME is a different beast). Let's break it down and compare it some alternatives. But first, a little backstory!
One of the things I had to understand on a deeper level is that Linux is NOT an operating system. It's just a kernel. Similarly to React which is just a library, not a framework. Here it's the biggest strength and weakness: it's like a modular synthesizer: there are an infinite number of combinations of components from which you will build your final OS. Freedom is great, it allows you to learn and tinker. It also has downsides - many times I've found myself in a rabbit hole of configuration, instead of actually accomplishing a task... not very friendly for a ADHD-adjacent mind. Also, how do you know if all the components are compatible with each other? Bear in mind, those components are not just programs like text editor or audio player, but crucial building-blocks like network configuration, monitor management etc.
Is there a cure for tinkering? Thankfully, yes! Fedora's immutable distros are designed in a way that prevents changing config files and installation of packages is not very convenient, so you'd rather stick to Flatpaks. It comes with support for containers, so if you want to try stuff and throw it away without consequences, just use that. It's a great strategy for a mission-critical machine (e.g. at work) where I don't want to touch anything I am not supposed to. Just focus at the task at hand and accept the limitations.
Sway is like Coke - "I like the idea of it more than I actually like it.". To get most (or actually anything) out of it you need to master the keyboard shortcuts, which I am fine with, except that they're not very ergonomic. It's easy to run into "emacs pinky" problem here, even after experimenting with a custom configuration I couldn't find a satisfying one. There's just too much reliance on a super/meta key. Notifications behave oddly, e.g. during app installation I saw multiple ones with random characters - perhaps the theme is misconfigured? Also, not every app is prepared for tiling window managers - for example DBeaver starts with a really janky welcome screen, because it doesn't expect it to be stretched more than it's background image size. Maybe in a setting where most things are done in terminal anyway this could be a solid option.
The main issue I've faced with Budgie is the menu bar and its app launcher - it seems that the longer the uptime, the slower the menu becomes. At some point, pressing "super" key opens only a "phantom" of the menu, that responds only when one starts typing name of the program to launch. After a while this gets old and you realize there are better choices without defects in core functionality.
This spin is an excellent example of how hard it is to have a dark mode set up consistently across different applications. GTK and Qt apps use different themes and are configured separately. Even after tweaking some apps just don't respect the settings, and what's worse, the colors between GTK and Qt apps don't match. KDE has a great utility for this called "Configure GNOME/GTK application style" which is more user friendly - you can install "breeze dark" GTK theme and you're good to go.
Sparky offers a very neat setup: Openbox with jgmenu and tint2 bar. It's fast and simple, but does not work well on laptops. Usually I turn off the built-in screen when using a external one, which is a scenario that this setup does not cover. I assume the menu tries to display itself on the built-in, which was set to primary. Messing around with xrandr does not help - only restarting the jgmenu does it. I would expect all of these things to work out of the box. Maybe if you're on a desktop with 1 screen you'll be satisfied.
In terms of inconsistent UI this one is a clear winner. Somehow I was able to open two instances of Geany next to each other, one light theme, the other one dark. Plus somehow it opens a network connection manager window each time after I log in. If that doesn't bother you, it's a great choice for reviving system based on ~20 years old CPU.
As you can see, what bothers me is the fragmentation of UI tools, that causes apps on the same system look completely different. Icons, colors, fonts, sizes and effects vary from app to app in an embarrassing way: not because their designs, but because those designs translate to pixels in ways they couldn't have imagined. Of course there are lots of other factors one might consider when choosing a distribution and desktop environment, but, if you value good design and you just want to get the job done, stick to KDE and Qt-powered apps.