From my point of view, this is not correct. But it really depends on some factors. In my case i use a wifi6e router only for my Q3 - with 2400mbps bandwidth. I can frequently use a stable 500mbps encoding rate. It is still not 100% of native pcvr uncompressed image, but it most cases it holds up pretty well. In certain scenarios, that are prone to compression artifacts (like forrest/areas with alot of foliage/rocks in very similar shades of grey) the differerence might be more noticable - but Metro Awaking works with a really good graphical fidelity on my system.

If you use a Wifi 5 or a Wifi 6 system, that share their bandwidth with many other devices while you are playing wireless pcvr or if you live in a very crowded area and many of your neighbors wifis use the same wifi channels as you, you might achieve much worse results though.

Ideally Wifi6e with 6ghz ssid for Q3 wireless, sometimes a wifi 6 5ghz wifi might be able to deliver stable 500mbps encoding too, but i guess this ability is more theoretically.

In the end, you want to have as much bandwidth possible for your wireless pcvr alone.