Isn't it stupid in জীবন্ত when they go to another country and everybody is speaking in japanese?

It's so us Japanese people can understand what they're saying without subtitles. I never noticed until my American cousins pointed it out. It happens in a lot of other shows from different countries too, not just Japanese anime.

I admit its silly,in one জীবন্ত they went to itally,everyone was speaking japanese.