"and if you're megacorp scale you can afford ops and bare metal you can depreciate over several years."

Don't assume this.

I worked at a 'big tech company' that made a very popular device.

Our IT was a disaster.

We made one of the world's most popular gadgety things - we couldn't make our email work.

Doing things the right way is extremely expensive sometimes, you have to pay zillions for consultants and they can screw it up.

If 'IT' is not a massive cost - often - the consideration is moot - move it to the cloud where things will work, and there is low overhead.

I'll bet $100 that Amazon is earning those margins easily.

Another example: why do companies use Windows instead of Linux which is free? Well, because Linux in a regular corp environment would be a huge nightmare. $50/employee to get something that works? That's dog-food heap. It's hardly a consideration, easy, just buy it. Maybe MS margins are huge. Who cares, because the value they created is monster.

Sometimes 'point and click' IT is worth a lot given all the risk factors etc. etc..