I'm gonna guess the reason is "because fuck you, that's why"

They simply don't have the resources to keep providing such advanced features. You'll have to go to the bigwigs like KDE if you want that.

The article is AI slop, I wish they dimply front loaded the video and the explanation given in there instead of full paragraphs of nothingness

Unfortunately, for the enthusiasts who had a left-aligned or vertical taskbar in Windows 10, you would have to settle for the fact that Microsoft’s data shows such users are really small when compared to the number of users who are asking for other newer features in the taskbar.