Back in the day, this is how we introduced AWS at a large company. We just did it. And once done, they couldn't deny that it cost a fraction of what we were paying our supplier and that things took minutes to set up rather than weeks. And that they worked a lot better.
Yes, there was shouting in meeting rooms. And yes, people said "you can't do this". Turns out they were wrong. A few years later I mentioned this to Werner Vogels. During a meeting. Where my CEO and CTO were present. And where everyone was feeling very good about us being one of AWS' biggest customers in our region.
So when someone says "you can't do that", sometimes you should make them prove it.
(At the time AWS was a good idea. Today dependence on a US service provider is a harder sell in Europe. The _first_ question you get today is if we can host it ourselves if we need to or if we can use a local service provider.)