You can host on AWS and still get hours-long downtime, as has happened recently. Whether the cost of trying to add another 9 to your uptime is worth the margin

You can host on AWS and still get hours-long downtime, as has happened recently. Whether the cost of trying to add another 9 to your uptime is worth the marginal benefit is for each company to decide. Each 9 gets exponentially more expensive. A lot of companies who think otherwise actually can afford (and will, sooner or later, be forced) to be down once in a while.