How many people will turn off AC and will not bake that cake, or wash clothes, when they know they're going off their own battery vs some electricity distributor's battery shared by others?

And if someone is dumb enough to do high load stuff on their own battery during a blackout, then it's less of a problem for others. Also individual failures will cover less homes.

Incentives and consequences will be different and differently spread.

And on individual level, you can also chose whether you want this or are fine with outage. (I'm against mandating this)