That makes sense. If I’m not wrong, Itch doesn’t allow (automated) translation of pages, so if you can only do separate builds, your only choices seem to be either put all language builds on the same page in the downloads section, or make separate pages (which can also be translated) with their own downloads section.
Either option seems cumbersome to me, at least if you plan to make updates semi-often. Maybe someone else might know if Itch supports a more automated way.
Actually now that I think about it, you can use the Butler tool from Itch, to automate builds of different languages. Although you might need some familiarity with the command line to do this comfortably.