Do you ACTUALLY think you can communicate with people at Amazon who truly know what's going on? If so, why do we see countless stories about people who have problems with Amazon, Google, et cetera, who can't communicate with them? Do you know of some special, magic way to get the skilled people to talk with you that the rest of us don't?
You act like being able to call Amazon, even if you could get someone on the line who knows something, is somehow better than having even just one good systems administrator. All of your ridiculous assumptions go right out the window when you have a sysadmin build, test and deploy your own hardware that you (via your sysadmin) have complete control over.
Security? You can't secure Amazon. You literally can't. If you wanted to, you'd have to buy the company, then you'd have to evaluate your whole S3 staff. If you hire a systems administrator, you have to vet your systems administrator and anyone else who has admin access, not a collection of tens of thousands of employees across the planet, any of whom could be stupid enough to visit the wrong web site using the wrong browser on the same computer as their keys.
Availability? My side projects have better uptime than Amazon.
Durability? Two geographically disparate locations and LTO, plus many mirrors, make things plenty durable.
When you're not a systems administrator, you can be forgiven for not understanding the big picture, but not for acting like you do.