Yes. I understand this better now. Basically, Ark needs very large and widespread ASPs or it has to use LN.

I shouldn't be calling it Ark so much as Arks. There isn't any single Ark like there is a single LN network. I think I knew this, but I wasn't thinking about the implications.

Maybe there is a world where Arks pay each other onchain in batch settlements once a day or something, but it starts to look even more like custody at that point.