> If you work on single-person "teams" maintaining something that is barely used and does not even have SLAs and can be shut down for hours then there's nothing preventing you from keeping all your eggs into a single basket.

There's a whole spectrum between that and "needs to go down for less than a minute per year". For every project/job/app that needs the AWS levels of resilience and availability, there are maybe a few 100k that don't, and none of those are the "barely-used, down for hours" type of thing either.

Having been a developer since the mid-90s, I am always fascinated by the thought that computer, server and/or network resilience is something that humanity only discovered in the last 15 years.

The global network handling payments and transactions worked with unnoticeable downtime for 30-odd years; millions of transactions per second, globally, and it was resilient enough to support that without noticeable or expensive downtime.