While Erenville's mom says that they should be deleted, it feels to me like she's trying to comfort and encourage us to go through with it.

I don't think the game is telling us the Endless didn't matter. If they didn't matter, why gray everything out and leave us with that silence after each section? Why take the time for Wuk to say goodbye to her surrogate mother, for Krile to bond with and say goodbye to her parents? For Erenville and his mom to spend those last fleeting moments together, if she didn't think it actually mattered? Her words and her actions do not line up. And I think this is intentional.

The problem wasn't that they didn't matter per say. But more that they couldn't be sustained without gorging on living souls at the expense of other worlds. It was something that had to be done because the only way to sustain it was to inflict terrible suffering upon othesr.