A bigger problem in NYC is electric water pumps: When the power goes out, the water stops when the water tower on the roof empties. This is mostly for buildings over 5-6 stories, older buildings were somewhat height-capped by municipal water pressure. No water means no toilets. Again, people don’t seem to know that toilets use gravity, a bucket will flush them. Big storm coming? Fill the bathtubs with water.
Only time I've had the water go out during a power outage was when I was in a house on well water. Otherwise, the pipes still have pressure. Gas furnaces won't work because of the blower, but the gas itself should still flow.
Gas hot water heaters without power vents are still readily available so its not hard to avoid this problem. If you really must have power venting the power requirements are low and can be powered by minimal backup generation or batteries.
Gas infrastructure is surprisingly resilient to widespread outages. That’s just a fact - how often are there widespread outages? It’s minuscule compared to electricity.
Except freezing, as Texas showed.
But the gas cooktop should work without problem if you light it with a match/lighter.
Again, definitely don't do this, but in a scenario where the alternative is that you freeze to death, it's possible to do so safely.
With modern combi boilers (tankless hot water + boiler) I believe your point stands.
edit: I mention this mainly because in Texas last winter some people froze to death during their electricity crisis.
Our prior home had pilot lights for the gas furnace, stove/ovens, and water heater. No electric igniters. All the items were pretty dated. But when the grid went down, they kept working.
I'm assuming any modern gas water heater is in a similar boat, with an electric starter instead of a pilot light - and it's much more difficult/annoying to light a water heater than a stove with a match.
The spark to light the pilot is a piezoelectric thing, manually operated. Newer models (less than ~15 years?) have a control board which is probably mostly mechanical, but does have a flashing LED. I assume that whatever drives the electronics is charged/powered by something that works off the differential of temperature in the chamber vs outside.
Personally, I'd rather have the generator if I had the space, but this would be a good option for people in townhouses and condos.
Similarly with gas ranges, you may need to manually light it, but the valves are usually manual (the oven is a different story).
Same goes for gas fireplaces that do not have a standing pilot and electrically actuated valves, which many newer appliances have.
It's not all that rare these days in cheap condo units (heck, even SFH...) in large cities to require power vent water heaters due to simply horrible architecture imo. Chimneys may not be a thing in some buildings, and locations of utility closets seem not optimized for venting at all.
A surprising number of gas appliances are slowly requiring electricity to run. I wonder if it's even possible to buy a gas clothes dryer these days without electronic controls without going through hoops? Certainly a fraction of the market.
Modern safety standards also drive "cop out" solutions to them like electronic interlocks with stovetops. I wonder how many modern gas stoves actually function without the A/C plugged in? Think I'll actually test this with my two units tonight!