That aside, I agree that there are a lot of secondary concerns that are important when running things in production but that aren't available out-of-the-box when you run something on AWS Lambda. I'm thinking about error monitoring, performance monitoring, logging,... All those things need to be set up and that's quite time-consuming.
However, I think that's more due to serverless being relatively new and not as mature as the traditional way of doing. I don't think it will take long before we'll have the equivalent for serverless of adding `gem 'newrelic_rpm'` to your Gemfile and magically having performance and error monitoring across your app.