How far is the one ultimate windows machine?

What I am talking about, is a single device running windows fulfilling all my needs. It's essentially a phone, but runs full windows, including the desktop and all it's apps. Normally, it will look like any other phone, or Windows phone. But if connected with a large display, it will able to switch to desktop mode and run full windows. I can think of two setups for this mode right now-

Wireless desktop: The phone will connect with a monitor/display through Miracast. And the phone itself will function like a mouse with it's motion sensors. Or, like a trackpad on it's touch screen. A bluetooth keyboard can be connected optionally. If no such keyboard is available, a touch screen keyboard displayed on the phone can do the makeshift job. So, I can get a desktop anywhere with a Miracast supported display.

Docked hub: This time, the phone will be docked to a hub supporting all the wired connectivity and ports like USB and other display ports. This dock will also charge the phone.

I don't want this device to run last generation PC games or video editing softwares. But certainly I would like to run visual studio and photoshop flawlessly. And all current desktop apps should run likewise. I would like this phone to effectively replace my work machine. I am ok with 128GB storage.

Right now, I think there is no HW limitation for this kind of device. We just need the right software. I know, Ubuntu is doing something similar. But I do not want an Ubuntu phone and it will hardly be able to replace my work machine with all those legacy apps. So, I am looking at you, Microsoft. When are they coming?

What do you people think about this?