Question about Gigabyte GeForce GTX 1060 G1 Gaming

Because there is basically no 1060 with SLI. This is reserved for the 1070/1080 models.

Because nowadays SLI is becoming more and more extinct and 2 GTX 1060s would possibly knock out a GTX 1080 in SLI.
Then the 1080 would no longer be worth it.