Of course this has been pushed to the side a bit in the rush towards shiny new pure-LLM approaches, but I think that’s more a function of a rapidly growing user base than of lost knowledge; the experts still keep this in mind, either in these terms or in terms of “Ensembles”. A great example is GPT-4, which AFAIU got its huge performance increase mostly through employing a “mixture of experts”, which is clearly a synonym for a society of agents or an ensemble of models.