Yes you are correct.
Nvidia's GPU's are pretty much untouchable, and pretty unobtainable (thanks scalpers)
But as you say, they are going flat out with MASSIVE GPU's and thousands of cores to create this super high end performance.
And this means, as you can using a lot of power to achieve this.
Doing a total turn-around and going all in on the low power market for portables would be a big shift for them.
I was sad what happened with the Tegra line (which I think is still used in some nice devices)
I recall the early graphics demo's of what Tegra was going to be able to do, and it looked stunning.
It was a shame something went wrong (I don't know what) and it was never continued to build into a full line of products.
They seemed to get off to an great start with much promise and then didn't follow through.....