That is absolutely and totally true, but 99.9999% of engineers are probably working on things like web apps or other high-level code.

The argument for FP was never that it was perfectly well-suited to every application-- merely that it was better-suited for your "typical" engineering tasks of writing business logic. FP, proof languages, and logic programming, are also all uniquely well-suited in situations that require correctness and formal verification (safety, aerospace, testing, etc).

To make a very broad, sweeping statement: if your project has a `node_modules` or a `venv`, then FP is the medicine you didn't know you needed. If you're writing low-level metal code / assembly, then you should already know you're not the target audience.