isolates like Basque that might have been invented

I don't think this is a valid linguistic take. There were tons of languages in Europe and Central Asia that are unknown to us. Then the Indo-Europeans expanded and mostly replaced the native linguistic groups. But I think linguists think the critical factor is geographic isolation, for instance Basques and Romanians are geographically isolated, or perhaps I should say geophysically.

distorted beyond recognition by the people who misuse them

This is not the only driving force of language evolution, although is true for imperialist languages like French, Spanish, and English. Languages evolve by generational shifts among native speakers too, eg this has happened with High German, I think.