Wait a minute…people touting V2G/V2H are saying it’s cheaper and more storage than a Powerwall, so they want it instead of paying up for permanent storage. So no, that is not the use case being discussed.
Again, in an emergency, yes, it would be useful. So would simply having a converter from the 12v out to 120v to power essential appliances (refrigerator). The notion of driving back and forth during a blackout to a working supercharger to keep your house going is about as practical as using your ICE car as a generator during an outage to power your house from the 12v plug and refueling at the gas station as needed.
V2G might be great in a rare emergency, but the right infrastructure is not there for general use and the right infrastructure is not to enable the car to be a primary backup source, but to have permanent stationary storage. With or without solar. I wouldn’t want to risk not being able to leave the area if necessary because I was running my fridge, TV or whatever instead.