Lots of API calls scales pretty well, as long as those APIs aren't all hitting the same database. You can do them in parallel. If you really need to you can build a view specific service on the backend to do them in parallel but with shorter round-trips and perhaps shared caches, and then deliver a more curated response to the frontend.

If you just have one single monolithic database, anything clever you do on the other levels just lets you survive until the single monolithic database becomes the bottle-neck, where unexpected load in one endpoint breaks several others.