The framework of thought I develop in the article says that you should use the managed cloud. If it is not what you are selling, others will do better. You may have an impression that you are saving in costs, but you are paying in opportunity cost by managing stuff yourself.

Only when you need to customize the solution for your own domain you should consider running it yourself. Companies like Uber are getting back to the cloud, others where the core business is developing software (like basecamp) are prefer to roll their own. If your core business is not the software development craft per se, like basecamp, you should be in the managed cloud, like Uber.

FWIW, kafka is perhaps one of the most glaring examples where people try to run it locally to save money, but end up paying a very high cost in stability and maintainance. Never run your own kafka is a mantra that I have seen more than one SRE team adopt.