I was very puzzled by your argument until I skimmed the video. You are associating functional programming with avoiding side effects. That’s a very Haskell-ish view of things but that’s not the heart of it.
The key idea of functional programming is that it’s easier to think of program as a composition of functions rather than as a list of statements and therefore functions should be first class values. That used to be controversial but frankly the idea won. We have seen lambdas go mainstream in most major languages and programming is more and more functional by the day.
The key idea of functional programming is that it’s easier to think of program as a composition of functions rather than as a list of statements and therefore functions should be first class values. That used to be controversial but frankly the idea won. We have seen lambdas go mainstream in most major languages and programming is more and more functional by the day.