First gaming needs very little bandwidth other than for downloading. Almost all online games need less than 500kbps, this lets people with small dsl connection play. Other than fast downloads gbit internet has little purpose. A family all watching different hd netflix movies likely does not use much more that a few hundred mbps.
Wifi in general is bad for games no matter how fancy the router it. The problem is your neighbors wifi usage and other radio devices that interfere. This causes lag spikes in games.
Finally the speed numbers you see are unrealistic marketing numbers. Even if you put the router on top of your pc you will get nowhere near 1gbit. In addition most end devices do not support the features the routers are using to get those fake numbers in the first place. Many are using non standard encoding that many devices do not support. The most common is routers use 4x4 mimo which need 4 antenna/feeds. Most end devices only have 2 antenna so the best they can do is 2x2 which mean a much cheaper router will run the same speed as the fancy one......and still neither router will be close to those magic numbers your see.
If you get 200-300mbps on a wifi connection you are doing very good.
BUT again you should not use wifi for online games and online games need very little bandwidth. When you see "gaming" router you just need since it is all marketing.