It actually is possible with raster tiles as well - see e.g. the local chapter work in France (
https://www.openstreetmap.fr ) or Germany (
https://www.openstreetmap.de ) or the osMap project with 10 different language versions (
https://wiki.openstreetmap.org/wiki/osMap ).
All those are produced with raster tiles.
But you are right as this approach does not scale well in regard to using it for all languages out there. So a vector tile stack is a better approach for just switching languages.