I was only making the point to show jrnation was wrong. The vita also does the remote play. It also works with the Xperia tablet so a screen similar in size to switch. But remember you can connect a dualshock controller to the devices making remote play actually really good.
Edit : i tried gta v on the go and it works really well. I also played bf4 online and actually got quite a few kills. It's quite a unique feature being able to play such powerful games on the go.
Switch can be played anywhere, can your vita/table does the remote play anywhere? Also, you only need to buy a Switch to play game but you need to buy both ps4 and vita/table to do that. What is good about spending too much like that just for playing on the go?
An Xperia + ps4 can be bought for 400€ the price of a ps4 Pro. Really not much. And with mobile data on your phone you can play it anywhere.