You are right that that is not required. That ArangoDB speaks HTTP doesn't mean it has to be exposed to the browser.

You can use Foxx to host your entire server-side application inside ArangoDB in some cases but in our experience, the best approach is having a middleground where the data-intensive server-side code lives in Foxx services and the client-facing part (e.g. server-side rendering) exists outside of it.

Foxx offers you the option to put backend logic directly inside the database; it's not an all-or-nothing decision.