As most people from my clubs were kinda well versed in english (common language, can't expect them to speak Croatian, or better any Croat language) as it was our main way to learn Japanese and to talk during trainings and tournaments. I trust him enough to say in his circle it's true...

Yeah, I'd say it has become much more common as of my last visit a couple years ago, but I still regularly bump into folks working in tourist-heavy parts of Tokyo who are limited to single word or short phrase English, and in mountain villages? Forget about it.

... and that I was too hasty to "assume" it's everyone over there (full populous).