this is a good question. idk
but we can take an educated guess and say that if they had a significant beneficial effect it would be a commonly known fact. on the other hand i do know that outdoor gardners like having worms in their soil. if we take these two pieces of information we can deduce that while they provide a beneficial service, they are not required nor needed in an indoor garden. most likely because whatever they create is provided by chemical fertilizers.
again this an educated guess. if anyone has the definitive answer i'd like to hear it