People were writing to UWP. There were hundreds of UWP apps that got cancelled and abandoned when Microsoft ditched their Windows Phone once Nadella got in. He kill Windows Phone, he killed native Edge (Chakra JS) and a lot of other stuff to focus fully on Cloud and then AI.
Before that ex-Microsoft guy was responsible for killing Nokia OS/Meego too in favor of Windows Phone - which got abandoned. What a train-wreck of errors leading to the mobile phone duopoly today.
UWP was more than just phones, https://blogs.windows.com/windowsdeveloper/2015/03/02/a-firs...
And Windows 11 was the reboot of Windows 10X,
Sure UWP never caught on, but you know why? Win32, which by the way is also Microsoft, was way to popular and more flexible. Devs weren't going to re-write their apps to UWP in order to support phones.