I suspect you're underestimating how difficult good UI really is. There's a reason UX is a separate career than development - it's a completely different skill set. And I speak as someone who has to do both (industrial HMI design) and I am well aware that I do the latter poorly.
Desktop GUIs were already solved in the 90s. Just stick with what works. Modern GUIs make the mistake of trying to force one GUI onto all platforms, giving us antifeatures like hamburger menus and vanishing scrollbars. As a desktop user, I'd rather the designers stayed as far away from my software as possible.