This is what I usually see from my phone when I am connected to the wifi. Since I am using Android I can also see the actual wifi bandwidth I am using thanks to a network monitor app- and I am nowhere close to 1200 Mbps! At the time this screenshot was taken my phone was using 15Kbps. When I started watching a youtube video the Rx rate was flipflopping between 6 and 1201 Mbps when the actual use was 2.4Mbps.
(Also it says my google home mini is using over 300Mbps constantly- which would equal 98.5TB/month)
When you hover it, it says "transmission rates of your wireless device".
So Tx/Rx Rate clearly does not mean "the current amount of data the device is using", so what does it mean exactly?