Do induction cooking tops work well on batteries (or generators)? IIRC our induction plate has two-phase power because it can pull more than 3.6kW.
An 8kW generator suitable for occasional use is only ~1,000$. A Powerwall 3 does 11kW continuous and peaks at 30kW for transitory loads like starting heavy equipment.
The most convenient solution where a generator automatically kicks in during a power outage requires an electrician and extra equipment, but there’s also real tradeoffs to having gas lines going to your home.
I think part of the problem with whole home backups is that they tend to be sized to a maximum load that is unusual or could be avoided with some effort. And that providing a backup for the essentials you actually need is relatively cheap and uncomplicated if you make some modest sacrifices.