Native look&feel makes for a consistent UX across apps. Users learn one set of conventions and UI controls that uniformly applies to all applications. In addition, all applications benefit from enhancements made to the native UI toolkit and integration with the OS (input methods, file dialogs, keyboard navigation, automations, …).
Moreover, web UIs tend to be less sophisticated and less power user friendly, due to HTML/CSS and browser API limitations. This unfortunately often carries over even to non-browser-based applications that however use a web-like UI.
There's a slightly deeper part to this which is that if I see a native UI toolkit in use, I can be at least relatively confident that the accessibility affordances I expect to be there haven't been half-arsed in some custom widget set implementation. That's part of the "one set of conventions" expectation you mention, but it's an important one. There's a lot of embedded knowledge in native widgets.
I don't personally believe it's ever been true that users want the same UI styling across apps. When given the option to customize the colors or layout of an app, users will do that. People want their applications to follow common UI patterns, but applications should have some kind of personality to them, otherwise they just look like Microsoft or Apple products
If you follow common UI patterns, your app will look like Apple or MS app, and there's nothing wrong with that. For a long laundry list of reasons: https://news.ycombinator.com/item?id=41368184
When apps have native look and feel, they have consistent behaviour, affordances and accessibility:
- buttons are labeled and placed correctly, and respond to expected input (including secondary focus and secondary action on MacOS, for example)
- dropdowns/selects behave correctly, and respond to expected input (for example, you can type to select in MacOS dropdowns).
- windows have OS-defined areas for drag/resize, for titles, for toolbars etc. They also appear correctly in the OS's window management tools (app switchers etc.)
- text inputs use the OS-default shortcuts and have access to OS-provided tools (e.g. spell checker)
- controls and windows respond correctly to keyboard and mouse. E.g. for a while Apple's own Catalyst apps didn't have the standard Cmd+Q to close the app. Many custom modals do not dismiss the modal on Escape
- context menus are standard in the places where you expect standard context menus. Well, app menus, too.
All good points, all true. But what’s also true is that current trend is to come up with arbitrary-looking controls even on apps made by Apple themselves. Nobody knows what native is supposed to look like. I’m not saying it’s good, it’s just what is happening.
It comes from macOS users, really.
On windows nothing looks native because nobody can make sense of what native looks like in current-year. On Linux, lol. Lmao.
On macOS? Your app better is native because it will stick out like a sore thumb if it isn’t and I won’t use it.
There are two types of apps: 1. the ones that professionals use and 2. the ones that consumers use.
for 1. they don't care if it looks native, as long as it works and is performant e.g. DAWs, Video Editing tools, Trading, etc.
2. likewise I don't think it matters that much.
my guess is the myth came from OS makers.