The common definition of what side effects are would argue otherwise. Functional programs definitely do adhere to maintaining referential transparency. FP is ab

The common definition of what side effects are would argue otherwise. Functional programs definitely do adhere to maintaining referential transparency. FP is about the world of the program, and the unknown. In the unknown, server failures and network issues happen, absolutely, but for the maintainability and local reasoning of the code, the rules of functional programming are followed so as many of those situations are handled. No paradigm can account for everything, and functional programming is one way of reasoning about the outside world in one of the safest ways you can. I think its totally unfair to consider FP as a garbage idea, there are tons of companies that follow these practices that rake in billions of dollars because their software works and is reliable. There plenty of valid criticisms of FP, but the world outside the JVM failing isn't one of them.