A typical example is a selection of the text. Because web apps are built using XML-based typesetting language from 80-s, everything is selectable by default. No matter how many layers of abstraction you put on top of that hackish foundation, you are still running it in the program (browser) designed to show text. So you can select buttons, navigation controls, images, sound players, etc. And it feels very native to web users.
But when you actually think about it, it's an insanely stupid UI choice that neither of proper UI frameworks would even consider. Sure, you can "opt-out" with recent CSS controls for selection, but it's again, a hack - the default choice of "everything is selectable" is made by default for you by the browser. What does it even mean - select button widget? Why would you enable this complicated selection functionality for your UI that allows users to select navigation buttons with a blue selection box? Of course, if your app needs this functionality - you can add it. But otherwise, it would be labeled as a very stupid UI choice. Yet, feels native to web.
Another example is zooming. Because UI apps written in web stack can't completely hide the fact that what they are doing is essentially trying to morph text primitives into complicated UI widgets (makes sense for 2024, right?), and the browser is essentially a text viewer, everything is zoomable and feels "native" to be able to zoom a web app. And yet, this rarely works as intended. In any other UI framework, making zoom functionality requires thinking about what and how you want to zoom and why. OS text size preferences are well handled by flutter, but sometimes you do want to add your own zoom functionality. In web though you just blindly zoom everything, often blowing off the layouts and that feels very "native" to web.
My point is, that I don't think UI frameworks should try to match the nativeness of web, especially when they start targeting the wasm platform. These couple of decades of proliferation of web frameworks built on top of HTML/JS/CSS should just wane in history as a dark period of software engineering.