For the majority of use cases, involving relatively static workloads, the cloud doesn't offer many financial benefits, as you say, particularly if you have access to a competent infrastructure engineer (which are harder to find than you'd think).

My experience of cloud has generally been around gambling websites, which have a very distinctive use case pattern, with daily peaks and troughs as well as seasonal peaks and troughs. There can be as much as a 25x difference in throughput between these occasions. For these sites it's a case of implement scaling natively in the cloud and stop worrying about capacity forecasting or invest millions in infrastructure upfront and watch it idle 90% of the time.

The financials simply work in this field, as I'd guess they do in serious online retailers with seasonal demand. However your average 2 web server, load balancer and single db server, not so much.