My data point in contrast to your suggestion is a company with more than a dozen developers, and a loose idea of "let's migrate from Heroku to AWS without planning much or actually educating our developers on how to use AWS to be as productive as they were in Heroku"; more than a year later, there was definitely some success to speak of, but there was a lot of realization that some of our systems were just fine on Heroku, and that we didn't have the DevOps talent to help us manage AWS better than Heroku was already helping us.