Why some startups are using AWS?
Or essentially: why someone who presumably knows what he's doing, is using AWS? I understand why the clueless do, because it's so convenient and Amazon marketing power is so strong - i had clients who had no concept of a dedicated server in their heads: for them it was either AWS/GCP/Azure, or buying a server and putting in their office - Amazon pushed other alternatives out of their brains with their marketing power - but the startup founders should still understand?
With AWS or any cloud you overpay 5x-100x. Why anyone rational would do it?
You pay a premium for flexibility. If you need a single dev server today and it is 50-50 that you will either need 100 servers next year or 3, then AWS or another cloud provider is the logical choice. AWS reserved instances can also give you a discount that makes the price competitive with regular dedicated servers. Note that you can also request a dedicated host on AWS EC2 and have a server reserved just for you.
What startup knows how to install, maintain and support infrastructure 24x7?