AMD is barely participating in the midrange where the real money in the consumer market is made. There might be volumes in low-end, but the margins are also very small. At the moment they only have RX 580 to "compete" with GTX 1060, even though it has the power consumption of a GTX 1080..
The difference in power consumption is important only if you game 24/7, otherwise it's negligible.
Here, enjoy some nice numbers from
computerbase.de:
The difference between 1060 FE and RX 580 in
idle is
4 Watts. The difference at
gaming is
77 Watts. The difference in
Youtube video is
2 Watts. If you leave the RX 580 idling with monitor off, it can turn off into
ZeroCore Power modus which consumes virtually no power, but I'm putting
1 W there just to be fair. Both cards perform virtually identical in games.
If you leave the computer running 24/7 and it
idles 12 hours, you
game 6 hours, watch a
Youtube for 2 hours and do other things non graphical intensive things for
4 hours the 1060 FE will consume: (12h*7W + 6h*111W + 2h*29W+4h*7W)/24h =
35W per hour and the RX 580 will consume (12h*1W + 6h*188W + 2h*31W+4h*11W)/24h =
50W per hour.
15 Watts/hour difference. Better have a fire extinguisher near your RX 580 system or it might catch fire! /s