Often it's not though.
It's a pain to admin for someone who knows nothing about it, and it's also a pain to have to do anything at all!
The power of the cloud for smaller shops is that the don't have to know what Synology is, or even give it a thought.
That you click point-click and set up an EC2 with some S3 and get rid of most admin knowledge/know-how is like magic.
That's the best reason to use it, even it costs 1-3x as much.
Once there is A) stability and predictability in requirements and B) sufficient scale - then - we can hire smart people such as yourself who know better, to set up something relatively simple, that will be relatively low maintenance (i.e. whatever you bill) and save some $.
Think Development vs. Operations cost.
If in dev, we have to wait for, mess with, configure things, it's very expensive, delays etc. and we don't want that.
Once there's enough predictability to determine 'unit cost' on the services side ... then you can 'cut costs' by moving to a slow-changing, custom solution, that is hopefully 'simple', as you say.