Benefiting someone else doesn't always need a sacrifice. These gods seem to want to protect Prismatica and the life it supports, so us simply living as social creatures is all they want from us.

I do...have theories as to why they brought outsiders, though. I believe the natives of this planet are somehow cursed by a hateful deity that nearly destroyed the world two centuries ago. That event, as far as I've been able to discover, is what heavily depleted this world of its Chroma supply. Local customs seem to indicate moonlacing used to be a major part of Prismal culture.