Does anyone heard a success stories from cloud usage?

Really, we(they) in the company decided to move in cloud everything from on-prem, it should save costs say them.

But, as result you anyway need DevOps, some complications with development, local environments and not only.

For not short career I faced some good examples, but it's more about unique situations, not a rule and a lot companies continue pay a lot for some small bunch of utility.

Maybe I'm wrong, but such topics about this hell heard a lot of timesand only on some conference: success stories (because they should say: success)