I feel similarly. I've tried in-home streaming from PS4 to a MacBook— obviously the encoding of the video signal isn't going to be as optimized or speedy as Google's backend, but still, the overall ping is sub-10ms and it's still a way worse experience than playing the same game on the TV, even for relatively slow paced action-adventure titles like HZD or RDR2.

I can't imagine trying to play something like a fighting game this way.

It worked great, in my experience. The most awesome thing about it was playing Dirt Rally 3 I believe, on a Motorola Droid/Milestone. A full PC game on a smartphone, pretty mind blowing at the time, and it was quite good even over 3G.