Why did Microsft put ARM in new Surface Pro?

[Geek-9pm]

Why? There is very little native software  for it.

Look at this:
https://www.theverge.com/2019/11/5/20948092/microsoft-surface-pro-x-review-arm-windows-10-apps-features-specs-price

The Surface Pro X is the computer Microsoft has tried to make for at least seven years. It is the computer Microsoft hopes will be the platform on which the future of Windows 10 is built. It is a beautiful, well-made hybrid tablet device that looks better than any other computer I’ve tried in at least the past year.

The entire reason for the Pro X to exist is as a platform to show off how Windows could run on an ARM processor — specifically one co-developed between Microsoft and Qualcomm. If you want to participate in that grand experiment, it will cost you: the base spec with a keyboard costs $1,138.99 while the model I’m testing runs $1,768.99.

He does not have much praise for it . Well, he did says-it looks good.
But why the ARM CPU?
The Surface Pro X is Microsoft's return to ARM-based Windows

The ARM-based architecture means that the Surface Pro X will support LTE out of the box. It should also be a stamina champ: Microsoft is promising 13 hours of battery life and a zero to 80 percent quick-charge time of under an hour...

I wail not  buy one yet. How about you? 

[Salmon Trout]

From the article -

It's unclear, though, if the market really wants an ARM-powered Windows laptop at the moment. The battery life of these devices, while impressive, has traditionally been at the expense of raw power. Will Microsoft's Surface Pro X -- and specifically, its custom SQ1 chipset -- solve this issue? If not, it could have limited appeal

A $1,000 device with the performance of an x86 device costing half that or less, just for 13 hours battery? And no audio jack. No thanks.

[Geek-9pm]

What 

And no audio jack.

No way, Jose.