I presume conlangs ignore this by design as fixed language. They are formed and mostly governed by rules, but the anthropological component of language never makes it into the design because there is no timeline of evolving usage.

And again, presuming here, but the outcome is a language that fails to adapt to the culture(s) that depends on it, and thereby becomes useless. Language, as we know it, evolved over an expansive period of time, from the first association of sounds to objects, now all the way to complex written grammar that includes some half-dozen tenses, some gendered, singulars/plurals, etc. We can describe things with written language that are otherwise indescribable with physical or spoken language, like the Portuguese saudade (a physical and emotional state of intense, fixated longing for someone or something that is absent, or which existed previously in a different state).