Live tiles were well researched in both psychology and UX. It wasnâ(TM)t just to unify the phone and PC. This was an era when touch-screens were suddenly becoming a thing in laptops, and Microsoft was losing market share to the iPad for consumption of information (web surfing, newspapers, etc). So the Surface and Surface Pro began, in addition to providing touch services on general touch screen laptops. The resolution on touch devices wasnâ(TM)t even as good at the time, and so the tiles were maybe larger than they should have been.
Like most vendors at the time, everyone thought touch would be _the_ thing. In reality, touch is terrible for productivity on a PC, lifting your hands off the keyboard and mouse and reaching for a giant screen at an ergonomically inaccessible location.
This was a part of UWP- having universal apps for PC, touch PCs, tablets, lesser ARM tablets, and to a lesser extent the phones. Unfortunately since developers resisted Windows 8, the users never received the experience of Windows 8 that was intended.