No one in Windows development community cares about WinUI, other than those with sunken costs that bought into the WinRT/UWP dream and now are stuck with a dead technology. Too many burned bridges since Windows 8 came out. If anything, this is Microsoft confirmation that they are unwilling to fix all the broken issues, and hoping the community will somehow still care.
This. Also DevExpress and Progress Telerik do not invest into their WinUI Controls at all, and that’s a sign they don’t buy into WinUI neither. WinForms and WPF are currently the only viable frameworks for Line of Business application. I have yet to see a WinUI3 application in the wild.
On a side note, I still love WPF after working in it for 10 years. Maybe it's just familiarity, and it's a little verbose at times, but man it's a great framework when you know that you're doing.