[nephs]

You are basically complaining that the client is loading too much data because you are sending them too much data.

You could publish the different languages in different folders/path, thus, using the static queries to build static pages.

If you want them on the same path while loading different language content dynamically, that migh not be the best use case for gatsby. In that case you probably need to load every translation for each of the included paths, but not every path with every language for all of the different pages.