Well, actually, that's not the same thing. Ethnocentrism doesn't really mean what you think it means either, but whatever. We're talking about what is more well-known
around the world. And actually, I can say that, without a doubt, that its Batman or at least I can make a very educated guess going off of global trends and evidence of cultural influence.
There are articles and books written about the long-reaching impact of superheroes on global culture, not just Batman, but Superman and Spider-Man and the Avengers too. Here are a few examples:
https://www.filmink.com.au/the-age-o...es-so-popular/
https://www.theguardian.com/culture/...man-so-popular
https://www.theatlantic.com/culture/...heroes/328461/
That write-up in the Guardian even describes Superman as the first "global superhero." And they're right. Superman (like Batman) is a global symbol, which is not surprising. For better or worse, American cultural exports have had a disproportionate impact on the world for the past 70 years because the U.S. has been a global superpower for about that long. As such, the U.S. has a significant and wide-reaching influence on global culture and media.
I also know this from firsthand knowledge. My father was born and raised in the Middle East, has never read a comic book in his life, and hates superhero movies with a passion. However, he can still instantly tell me who Superman and Batman are. BUT, if I asked him what One Piece was, his response would be "what is One Piece?" And again, that's not because Batman or Superman are better. One Piece just hasn't been around as long as they have.