It's not about lock in or getting access to the side-show features available in other clouds. For a large company there is significant business risk in having a

It's not about lock in or getting access to the side-show features available in other clouds. For a large company there is significant business risk in having all your infrastructure in one place. A billing error or some other misunderstanding could have catastrophic consequences. I've heard of absurdly close calls here. I know that one public company dependent on AWS maintains multiple accounts to lower the risk of this happening. Multi-cloud is another way to mitigate that risk.