Maybe in this case it has to do with transfer speed and cost. Although I've never used LTC and ZIL, I do use DGB a lot. Although sometimes not everyone accepts, but several times I negotiated and was accepted. Because the network is not congested, so it is quite fast and the cost is quite cheap. If I'm not mistaken it costs around 50$/worth about 1100DGB at a cost of 0.2 DGB. Although this is like a P2P transaction it is not an official transaction, because my country forbids using crypto as a legal tender.