Honestly this is the only complaint I agree with. KDE plasma desktop and its configurability looks and feels great... but all their in house actual windowed applications like Konsole and Kate are mediocre at best. All that duplicated effort seems wasteful.
It's honestly just Konsole. Kate is very good, you can legitimately use it as a vscode replacement if you want. Dolphin is also the best file manager and it's not even close.
And then kmail... kmail is bad.
I wonder how much QT has to do with this. AFAIK the only _decent_ bindings are still C++ and Python. For KDE it might just be C++?
There's plenty of valid criticism of GTK but choosing C over C++ isn't one of them. It seems like there is a new Rust GTK app every week, and other languages as well, thanks to the availability of bindings.
I'm curious how long relying on C++ contributions is going to last.