^^^
1) Less than 1% (just a guess) of the population can have that option (cost and or no place to put it).
2) I wonder what the environmental impact is of EVERY car owner having a power wall.
3) If I need to have an extra vehicle just sitting around because having power to recharge the EV is that unreliable, then I don't need an EV other than to have a cool toy to talk about at parties.

So, you're saying you don't believe in back up generators or gas cans either?

OK, fair enough, something to consider.
Is it legal to store gasoline in CA? How much gas would it take to charge an EV? Where does a renter or condo owner put the fuel and a generator with enough capacity to do the charging? Is this a viable solution for everyone or just one percenters?

Actually, my point is that a power wall is nothing more than a can of gas or a backup generator which I would guess you have one or both.
I don't have one but after taking 2 minutes to read about them on Tesla's site, it looks like they are nothing more than backup. Whether they are charged off the grid or solar seems irrelevant.
Now for stored gas, my guess is that most condo HOA's in the US would discourage the storage of gasoline.