Nvidia can match/exceed anything AMD can offer, they have more experience with low power tablet sized chips thanks to the Tegra line than AMD does and are a bigger company with more resources.

Bottom line is I doubt shrinking the actual PS4 is feasible for a long time if ever. The chip simply was not made to be shrunk down that much and operate at a 12 watt-ish power draw max (excluding the screen which eats up more power).

Sony would have to get a custom chip most likely and start from a library of 0.

Nintendo could very easily counter with a new Switch with a Nvidia chip that's just as good or better, but still have backwards compatibility with hundreds and hundreds of original Switch titles too.

The other problem is the RAM ... GDDR5 RAM is way too hot and power hungry for a mobile chip. It's not just the GPU. Change the RAM though and you radically alter games that can run on the system. 

He's saying just because the PS4 is selling more now, that means less people want the Switch. He's thinking a console 4 1/2 years into its life shouldn't be selling better and that means the NS isn't doing as well. That's wrong. Older consoles have far more momentum than brand new ones. The PS4 is selling better than itself at launch. Does that mean less people want a PS4 and more people want a PS4? How well the Switch does in the future doesn't matter here. The point is that the PS4's current sales numbers don't indicate that people don't want the Switch.

I'm looking for the video of the PlayStation Switch but I can't find it... Damn...