In game ping

The speed of your connection will not affect the latency. It will be the distance between you and the game server. The further the server is, the higher the ping. Servers in California and Texas tend to have the worst pings for North American servers. Those closer to Canada, either Chicago or Seattle can have much lower ones but server location is all dependent on where the game developer decided to keep them.

A gaming router would not improve the pings unfortunately. At most maybe a couple milliseconds but not enough to make a difference. 

I too am on gigabit fibre and I see pings between 70ms and 100ms depending on the game I play. Some servers are closer than others. The odd time I'll come across a server hosted in Chicago and get a 40-50ms ping but only one game had that recently, and it's not a very popular one these days. It did have a few in the 25-40ms range but they weren't game modes I preferred. It was an older game that let users host their own servers pretty much anywhere rather than forcing people to use only the game studio's own servers.