Badly setup wifi might be a problem, but good setup won't care. I'm running WIfi and have no trouble playing 8v8 games, that is if they don't crush someones else connection kappa. I'm also not having any trouble streaming 1080p and playing FAF on Wifi connection.
If anything I would run a speed test of your connection to see how fast is your upload as some older and slower connections can be bottle-necking here even when sporting quite reasonable download speed.
And I'm speaking it from experience, few years ago when I started playing faf I also was surprised that playing anything bigger than 5v5 might become lag fest due to my connection even though I had no such troubles with other games. I thought that having 4Mbit/s download would be good enough, turns out I had abysmal upload rate that would tend to bottleneck bigger games.