For many that's a rare problem
Well for me it is a rare problem, say 0-3 blackouts a year, and 0-1 lasting more then a few hours. So less important then say “how does it deal with a long trip I make once a year”.
On the other hand a 3 day power outage in the winter (not normal, but not unusual) is no joke. It is enough of a “no joke” the most houses around here have an external input for a generator or other 240V power source. Mine in particular will power the house’s heating (well the water circulation pumps and the furnace ignition), as well as the kitchen fridge/freezer, and the wall outlets & ceiling fixtures in a few rooms. Which is nice because it means for around 500W you get heat, lights, and a way to keep the beer cold. You don’t get the stove (electric, high draw 240V), or the microwave (I mean you could drag it over to an outlet that has power, but a microwave is pretty hard on a portable generator), or the coffee maker (again it can be dragged to a outlet, but it is hard on a generator).
I have a big ass APEX battery something like 3kWh and does 240V output. It is way happier with the coffee maker then my little generator. It is decent in general for running the house’s limited “backup power” mode. Except it will only run it for around 6 hours. On the other hand my EV does have 120V 15A out, which won’t run my home heating system, but it will power the APEX. The EV has around 100kWh in the battery, so it’ll run the APEX and indirectly the house for a very long time.
Or to be fair a really crap Harbor Freight portable generator that will last one outage and then die a horrible death could be used to feed the APEX, and the APEX can weather all the rough loads and ramp-up/down and generally make life easier for the generator.
However that is all a bit of a diversion from my main point. It may be a bit uncommon to have a 3 day winter power outage here (although the power outages tend to happen during rough weather, so -20F ice storms tend to bring the power outages, and the bad weather makes it harder to get linemen where they need to be and equipment to them, so yeah the long outages tend to be winters!)...but they aren’t even rare. Live here for a decade and you will have about three of them. Having it well below freezing and no power and no heat means whatever water you have is going to freeze and expand. A lot of heating around here uses water to transit the heat, so the normal “nothing will freeze and burst in the first day, maybe two” you get “well at least one of those pipes runs in the low insulation areas under the roof to help clear ice sheets...and that one will freeze in a few hours. Plus others will freeze pretty early as well, maybe not day one, but you arne’t getting through much of day two without many thousands of dollars of damage.
So try not to over generalize from your local power stability and lack of winter power oriented damage. This kind of feature can be worth tens of thousands of dollars every few years.
I’m less sure that there are a lot of places you can save enough from buying power at low rate times and using it from you down battery at higher rate times (I think there are clearly places with a 3x rate difference, but even so it is around 20 per kWh, and most EVs have more like 40kWh batteries, not the 98kWh battery I have, so the savings tops out around $8/day and that isn’t a lot even if it doesn’t put any noticeable extra strain on your EV’s lifetime it has a super low payback. Then again maybe some places have a much larger kWh cost and a bigger off-peak discount? I definitely don’t know any place it is a fast payback though.