The capex vs opex argument in cloud is more about having better transparency on your infra costs on a monthly/quarterly/yearly basis. With DCs you need to make large upfront purchases for todays and the next 3 years needs. If you under estimate you’ll be unable to grow further. If you over estimate you’ll be stuck with a bunch of unused infra.

Now say you want to spin up a new feature/product. Can you accurately forecast the compute needs? How difficult would it be to get a large capex PO out through your internal orgs on the unreleased non-revenue functionality.

Compare that to cloud where you pay for what you need. Calculating marginal cost is much easier, and securing budget on an ongoing basis to pay for clouds opex is also much easier, as you can easily show to finance the profit margins.

As the other commentor has mentioned, much easier for management to manage costs and assign to cost centers or buckets. It's a big difference to track consumption monthly based on actual instead of straight line depre, eg. depreciation hits even if everything turned off