Makes sense since a lot of networks don't have access to speed. The highest speeds in my area are around 150MBps, so 5-6GBps or whatever is a perfectly fine upper bound for me. Range and congestion however has been an issue.
You can still make use of more. Local video streaming from your PC to tv, file transfers between nearby devices etc.
Modern wifi is fast enough that using cables is often not required.
It's nice to have the fastest Wi-Fi possible even if your upstream internet is slower. Sometimes you want to transfer files locally between devices, or run backups etc. Faster Wi-Fi here can make a huge difference to those tasks.