Permabanned
Even the best WiFi isn't good enough for fighting games.
Possibly not, dont think I have played one since Battle Arena Toshinden though.
However both myself(PC) and Son(PC/Xbox) game online a lot and have no issues using 802.11ac wifi. Just that a good wifi setup is not as poor as it used to be. That said I would prefer wired and anything near the router is wired.
Shame Series X is not WiFi 6, would be an excuse to upgrade.