Many "modern" desktop apps rely on web based technology which throws them back ages in terms of UI and UX
For an even more WTF experience, look at how CSS had defined how web apps could use the system-defined colours for UI elements, but then it was deprecated due to a very thin "insufficient" and "security/privacy" argument:
Obviously they could be made sufficient (imagine if JS was deprecated because it was deemed "insufficient" for making applications behave natively...), and things like Electron could use them without worrying about "security" since it's not in pages served over the network.
(That "security/privacy" argument is really thin, especially when considering how much less customisable the colours have become in newer OSs!)
Unfortunately, "because security!" is currently a trump card that wins all arguments. On the one hand I get it, security has been pretty neglected in the industry over the past decades, but I think we also really ought to have a conversation about the costs of security.
The ultimate state of perfect security for a system is a dead rock. Everything that's interesting and useful can only happen in the state of some lack of security.
For an even more WTF experience, look at how CSS had defined how web apps could use the system-defined colours for UI elements, but then it was deprecated due to a very thin "insufficient" and "security/privacy" argument:
https://www.w3.org/TR/css-color-4/#deprecated-system-colors
Obviously they could be made sufficient (imagine if JS was deprecated because it was deemed "insufficient" for making applications behave natively...), and things like Electron could use them without worrying about "security" since it's not in pages served over the network.
(That "security/privacy" argument is really thin, especially when considering how much less customisable the colours have become in newer OSs!)