Well, with Android/Chrome OS they just recently released Jetpack Compose Material 3 Adaptive which is further iteration by Google to try to unify UI development between form factors [1]. And there's the breaking changes with every major version of Android [2]. Then there are the incompatibilities for Android apps for Chrome OS [3].
You can shit on Microsoft all you want, but those listed APIs still work. People expect Microsoft APIs to exist essentially forever, so every breaking change pretty much has to be a new API.
Having a single simple API for developing across different devices and inputs that automatically provides great UX across the board just isn't possible. It's going to be complex and it's on the developer to cater to each device. An API to cater to everything is literally web APIs.
Tell me you never used those APIs, without telling me.
No they don't work, that is why each iteraction requires a rewrite.
WinRT for Windows 10, isn't the same as WinRT for Windows 8.1, isn't the same as WinRT for Windows 8.
WinUI 3.0 has features that are Windows 11 only, although Project Reunion promised compatibility across Windows 10 and 11, it is still quite far from Win 2.0 in features and tooling, years away in fact.
Likewise the WinRT used by WinUI 3.0 in Win32 mode, isn't the same as WinRT used by WinUI 2.0 in UWP mode. Meaning the set of underlying COM plumbing differs in behaviour and exposed set of interfaces.
And I will leave it here, as Github issues and discussions already have plenty of rant material on the matter from the Windows developer community.
I'm not saying that the newer APIs are backwards compatible with the older ones. I'm saying that they're not which is why they are different APIs. WinRT is a bit different since you target a Windows SDK. But, likewise newer SDKs have APIs that are not backwards compatible.
What I am saying is that the older APIs are forwards compatible with newer versions of Windows. On Windows 11, you can still run applications using those old APIs.
On Android and iOS, your old app may break when running on a newer OS version.
Microsoft doesn't have the luxury of changing the behavior of older APIs on newer versions of Windows, so they end up having to make completely new ones.
As anyone can imagine by that list, every new acronym requires a rewrite, and most folks that aren't on Microsoft pay list no longer care.