What do you mean "twice in 20 years"?
2019:
"California’s largest utility is under severe scrutiny by state regulators and customers over its rolling blackouts that have left millions of people without power.
Just two weeks after a massive power shut-off that the company acknowledged it mishandled, Pacific Gas & Electric announced on Wednesday that it will cut electricity to 179,000 customers in California in the face of a new wildfire threat. Southern California Edison, the state’s second-largest investor-owned utility, also warned on Wednesday of power outages to 308,000 customers."
https://www.cnbc.com/2019/10/23/pge-rebuked-over-imposing-bl...
That's at least 1 and possibly 3 power cutoffs (not outages, deliberate cuts) just in 2019.
Several days so far in 2020, with millions affected.
https://www.vox.com/2020/8/15/21370128/california-blackouts-...
And the year is still young.
And of course the energy crisis in 2000-2001 caused many, many blackouts over the course of two years, it's not the single incident you are implying.
https://en.wikipedia.org/wiki/California_electricity_crisis
> far shorter than the Berlin outage
Shifting goal posts. This was a single outage affecting 30K people. Just the one Chicago outage affected 800K people, that's 26x more people. This isn't comparing Apples and Oranges, this is comparing Apples and Aircraft Carriers.
And most of the others are over 100K people. And there are multiple ones per city. Per year. And I stopped looking after it was clear that many cities were affected by much larger outages multiple times a year. My guess is that outages affecting only 30K people just didn't make the news.
> The grid can't target perfect reliability
Yes, being resilient against construction workers cutting the cable is difficult. However, being resilient against storms, storms that occur just about every year should be something you can expect, and in non-third-world countries is something that you actually can expect. That doesn't mean there never is storm damage, just that power isn't routinely cut when there's a storm as seems to be the case. Or when the weather is hot.
Austria has much worse snow storms and ice than what we saw that winter in Detroit, every year. And avalanches. Yet I've never seen or experienced anything like that power outage. And it doesn't look like anything substantial has changed. The US has been under-investing in infrastructure for many decades, and it shows.
If you don't believe it, visit other places.
> reliability will be higher with lower population density
New York has a low population density? Chicago? The Bay Area?