This is what a lot of people miss when they talk about moving to/from cloud providers. The marginal cost to add X more servers in the cloud is basically nothing

This is what a lot of people miss when they talk about moving to/from cloud providers. The marginal cost to add X more servers in the cloud is basically nothing, whereas to set up a new rack for on-prem requires requirements gathering, purchase orders, finance approvals, someone being at the dock when the UPS truck arrives, rack and stacks, etc. Those are one-time, yet very real costs. These fall under cap-ex which accounting-wise is treated very differently than op-ex. Now the cost in the cloud bakes all that in, and is distributed around with other users of the provider. Your accounting models are also easier ("pay for what you use"). Couple that with the very well known fact that AWS has outrageous data egress charges and there are patterns that can emerge where you're still in cloud but not racking up massive outbound data charges.