The docs say "Hydrogen can only be used to build Shopify web storefronts. Currently, Hydrogen doesn't support building other types of custom storefronts, including mobile apps, video games, and smart devices."

I get that the shopify components expect to receive shopify-format data, but are there other restrictions we should understand? The docs do say Hydrogen apps can hit 3rd-party API's, so how do we think about the dividing line between what Hydrogen can and can't do?