If you actually take a graduate level course on scientific methodology or on the philosophy of science, you will learn that “falsifiability” is no longer a viable standard for scientific validity. This is because, logically, no claim is falsifiable: one can always adjust background beliefs to evade a logical contradiction. See the Duheim-Quine thesis.
Moreover, if your argument were correct, we would have to reject evolutionary inferences altogether! What you say about the cognitive system is true for, e.g. the immune system or the endocrine system. But that’s ridiculous. Evolutionary claims are part of the bedrock of the so-called Modern Synthesis in the biological sciences of the last hundred years. Yours is similar to bad arguments made by creationists.
Your “No True Scotsman” response is just deeply confused about what evolutionary psychology even is. What a mess.