I don't think it's going to be rich households vs poor households, it's going to be sparse residential areas vs dense residential areas, respectively.
Because, in all honesty, you aren't going off-grid if you don't exclusively own the roof (for solar). And because solar nets so little power per square meter, you need a lot of panels per household.
A single roof over a six-floor apartment building just isn't going to have enough surface area to let the residents go off-grid.
A single roof over a single-family home in the suburbs is generally enough.
I have solar that covers all my usage, and net metering, but I still need to ~€30 per month to cover the cost of storing it and taking it back from the grid. I'd be paying around €120 if I didn't have solar.
Tesla Electric customers report making as much as $150 a day: https://electrek.co/2023/07/05/tesla-electric-customers-repo...
Add in 2 EV's per household and you won't be able to do it all year round without grid connections.
The only way that's physically possible is if these EV's are electric scooters.