The idea that Neanderthals were dumb and brutish came about because the first fairly complete Neanderthal skeleton we found was that of an elderly man whose body was warped by arthritis, to the point that he appeared stooped and gorilla-like. That in itself tells us how sophisticated they were – either they were willing to care for a non-productive tribe member, or they valued tasks such as weaving fishing nets or telling sagas which could be performed by a person who could barely move.
Nor were they all that ugly. Craggy, yes, but than can be attractive in a man
and even the women could be attractive in a weird, slightly alien way:
And we know they were quite sophisticated people, who made 3-ply string and had at least some idea of art and pattern, so far from being crude and chimp-like they may well have had plaited hair with feathers and flowers in it, luxurious fur capes and decorative tattoos.