For my leaf, I have a simple 12v pure sine wave AC inverter. In a pinch I can turn on my car and hook up the inverter to the lead acid battery, which is charged from the leafs main battery.
If you want to plug an EV in to charge, put a circuit in and have fun.
If you want to backfeed any power to the grid, well, you need an application with the power company (which usually has an application fee), plans that often have to be reviewed and approved (which is a giant pain in some areas, mine included), then the new rate schedules, inspections of the generating facilities for initial operation and continuing operation, and it's a giant pain in the rear. Plus, there's really no strong incentives to actually do this sort of thing, financially - if you've got a solar install, OK, but just a battery... eh. A backup generator is an awful lot cheaper in most cases.
Something tells me that it will be a while before we have EVs with built-in 240V split-phase inverters.
[1] https://www.hyundai.com/worldwide/en/company/newsroom/hyunda...
IMO, a good V2L setup needs to have split phase 240V in the US. But that would add significantly to the manufacturing cost of the car, so I won't hold my breath.