Well, I think language isn't a problem if the song is composed from the groundup for a language, the problem is they normally want to keep the meaning and sentences of the song, so we end up with messy songs like some Beyonce spanish songs, or some of the Shakira dual tracks. It's not a big deal when the translated section is its own thing, like English version of Despacito. Most of the times, the issue comes from having a main version and getting exposed later to the translation, which will always be more awkward.
I honestly think that language is one of the least important things in what makes japanese music what it is. For example, the Your Name OST in english still feels like japanese music for me, but the lyrics still work, IMO.
