You could say the same for a 4.3 inch phone vs. a 10 inch 2.5k, and, soon, 12 inch 4k Android tablet. And if you want radically different capabilities, phones have SIMs that are assumed to be single-owner while most Android tablets are multi-user. Processors range from 800Mhz single-processor with mediocre bus performance, to quad-core 2.3 Ghz. There really isn't any interactive software you wouldn't run on a mobile device, and if you grok Fragment on Android, you can write for any device geometry from a single code-base.
The true boundary between mobile and desktop computing is numeric computation. You don't want to mine bitcoin or your stock market rocket science on a mobile device, mainly due to burning through the battery in a trice.
It never made sense for things called Windows not to have a unified pool of apps. This is a significant improvement.
What about things like Keyboard and Mouse vs. Touch? Network Quality (Persistent highspeed connection vs. intermittent limited quality)? Available storage space (You can consider most desktop machines (1/4 terrabyte or better) unlimited in comparison to mobile devices? Multiple Large displays (not on all I know) vs. single small display? There's alot more there than numeric computation abilities alone to take into consideration.
There are reasons to sit in front of a couple large non-touch displays attached to an uncompromising $5000+ computer. But that's for the <5% that need that and they know who they are.
The other 95% will benefit from being freed from their veal cubicles and looking up at human faces while walking around.
As for mouse vs touch etc. I agree, I think. Microsoft should have made a touch OS that isn't Windows. They might get Windows fully evolved to span that gap about the time Android takes away the enterprise business.
The true boundary between mobile and desktop computing is numeric computation. You don't want to mine bitcoin or your stock market rocket science on a mobile device, mainly due to burning through the battery in a trice.
It never made sense for things called Windows not to have a unified pool of apps. This is a significant improvement.