It's one of the big ironies of the EU - every time it gets larger (good! increases market size) it also gets more fragmented in terms of languages, retained local rules etc. (bad, obviously).

Now up to 24 official languages and still potentially growing in the future (although this is a bit of an overcount because some of them are mutually intelligible to various degrees, it's still a lot).

It's interesting to think that at the time of original ECSC treaty there were only four languages (French, German, Dutch and Italian). That's just about manageable, now it is a bit of an issue