The sad thing is that by the 1990s we'd figured out how to do good UI design for desktops, but then we promptly forgot every single bit of that knowledge when the web came along.
Java applets could use Swing to get a normal-ish desktop UI and still be close to the web. But we keep trying to cram a UI framework into HTML/CSS.
The standards are slowly mutating and eventually they may provide a good UI framework.
JavaFX and Qt are both modern UI frameworks. Both provide a drag-n-drop interface to design applications using standard widgets such as lists and tabbed panes etc. You can modify the styling with CSS (at least in JavaFX, I don't have much experience with Qt). But the final layout spec is done in FXML or the Qt XML format - the XML has <TabbedPane>s and <HBox/VBox/GridBox> and <Button>, with CSS used to style these elements and dictate their visual properties. Instead of divs and spans hacked with css/JS into becoming scrolling lists and tabbed panes or horizontal container boxes.
I know the basics of HTML/CSS and it took me half an hour to figure out how to put 3 images side by side. Because divs can't represent that naturally - I had to use weird css and put 3 divs inside the outer div. In JavaFX you would put an HBox and drag three Images into it and it just works, because a HBox represents a UI concept instead of a document markup concept.
<div><img ...><img ...><img ...></div>
? But you're right, the web isn't a UI platform. It's designed for to produce things that are like Microsoft Word documents. Web-apps are like using MSWord's scripting and text layout to produce a MSWord-app. Yeah, one can do it, but it's like cutting a steak with a spoon.
I haven't used JavaFX in a while but I'd bet there's a checkbox you can toggle in the builder GUI to control how an HBox overflows.
The solution for HTML/CSS was to give the outer div "white-space: nowrap" and the three inner divs (with images inside them) "display: inline-block".
Naturally also Web based ones since early 2000's.
Share the feeling, everything is so much easier in native toolkits.
There is some hope though thanks to Web Components and Houdini.
This is (still) a problem with OSes. Mobile improved the situation a bit but not really that much. I am now reluctant to install mobile apps since virtually every mobile app is a potential vector for who knows who to spy on me. Mobile apps are isolated enough that they're unlikely to trash the device but they still have huge security isolation problems.
TL;DR: endpoint OSes suck so the web won in spite of being a crappy UI platform.