It all depends on the quality of your router, the quality of your wifi adapter in your computer, how far the distance from your router to your wifi adapter, how many other wifi networks around in your area.
If all those factors are good, there is hardly any difference between wifi and wired.
Wifi is always worse then wired connection. It`s unstable even if the distance between router and computer is 2 meters. For gaming, internet - this is ok, but in mining this is losses. I calculated difference - it have been about 10%. Router was about 4 meters from rig
Definitely, 5Ghz wifi is OK, it's fast and things but sometimes it lost its connection not to mention that the wired connection is definintely A LOT stable because it is wired. Even for gaming wifi sometimes sucks because there's lost packet and stuff and that's kinda not worth it for business and it's for mining which requires more intensive work, also wired is cheaper, I can't see why people prefer to buy expensive wifi than ultra cheap cat6 LAN cable
Yes, wired is cheaper and possibly slightly better, but who wants those long nasty cables running through your whole house/apartment. Wifi is so much cleaner looking and don't mess your floor up.