There are a few ways! I have separate Firefox profiles for everything.
The least effort way is to visit about:profiles, then you get a list of them all and can add/remove them. I have it bookmarked or pinned as a tab in all of my different profiles.
Second, but takes more effort is you can make desktop or start menu shortcuts to the profiles. In short (on windows at least) you copy the Firefox shortcut, edit it, then add -p “Profile Name”. There might be more to it? Maybe good to Google this one for a better description. But I literally have a start menu shortcut for all like 7 of mine, then it’s just like launching a different application.
I guess one reason why no one is paying attention to it is because is the Wi-Fi speed usually the limiting factor? In my case I’ve rarely ever maxed out my Wi-Fi 6 speeds. Typically the host or the network that I’m on that is the limiting factor.
Although I’m also in the US so I know where not know for having the fastest internet in the world. Maybe in other areas of the world WiFi 7 might be more useful.