There's a project called wifibroadcast (https://befinitiv.wordpress.com/wifibroadcast-analog-like-tr...) that allows to pipe data between two WiFi nodes in monitor mode so there's no need for association.
You can do hard-realtime over the circuit-switched substrate of the public Internet, though. "Two tin-cans and string" (i.e. two modems and the PSTN network) still works surprisingly well for (low-bandwidth) real-time control across vast distances. You can even get a decent hard-realtime SLA (much better than that of wi-fi or cellular data service) when one of the ends is a cell phone on 3G with its headphone jack plugged into a modem.
Yes. You do not do hard real time over the public Internet.
(I've actually had the experience of driving a full-sized vehicle over WiFi. When we built our DARPA Grand Challenge vehicle in 2004, we had the test capability of driving it remotely over WiFi, from a control station with a game steering wheel and pedals. Worked fine technically, difficult to drive. 100ms of no signal and the stall timer slammed on the brakes. Self-driving in the "cloud" is not where you want to go.)