I think a major problem with Serverless architecture, as much as it is awesome, is that to manage it you would need to be already familiar with the underlying systems that provide it. Hence, it would imperative that you already have worked with the architecture you are planning on replacing.

Unless there is some elegant factor to Serverless that I am missing. I just can't shake the feeling that at the end of the day this is just a sales tactic.

Nevertheless, I opt to use serverless BaaS solutions whenever I can afford to.