I agree with you, but the point of the type systems is that they allow you to keep your purity while still giving the flexibility. A powerful type system is closer to a very powerful linter.
Example: it is fine to have internal state in pure functions, as long as that state doesn't break purity. Haskell's State Monad helps you ensure that. If you're doing FP in a multi-paradigm language, however, it's easy to make a mutation hell.
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I think the problem with FP and OOP are never with the core concepts themselves, but rather the implementations in the form of multiparadigm languages. They make the escape hatches are too convenient and bad engineering is too accessible.
Example: it is fine to have internal state in pure functions, as long as that state doesn't break purity. Haskell's State Monad helps you ensure that. If you're doing FP in a multi-paradigm language, however, it's easy to make a mutation hell.
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I think the problem with FP and OOP are never with the core concepts themselves, but rather the implementations in the form of multiparadigm languages. They make the escape hatches are too convenient and bad engineering is too accessible.