But even comparing the apples to the oranges, this HN status page someone else pointed out https://hn.hund.io/ seems to show that HN has had more than one outage in just the past month. All but today's and last night's being quite short, but still. Sometimes you need some extra complexity if you want to make it to zero downtime overall.
That's not something the HN website needs but I think AWS is doing fine even if that's your point of comparison.
Edit - HN is on AWS now. https://news.ycombinator.com/item?id=32026571