Via an AUA conducted on Reddit by the Windows Developer team, Microsoft has confirmed that it is focusing on improving Windows 11's performance especially when it comes to the UI performance.
Beta Channel build gets Taskbar, File Explorer improvements, ISOs available
windows 11 insider preview
How to set different wallpapers on different monitors in Windows 11
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Windows ui 3 RSS
It appears that UWP is on the way out as Microsoft has recently published guidance about how to migrate from UWP to Windows App SDK, which has been highlighted as the new strategic direction.