Also, in the U.S. there seem to be an extremely large number of people who accuse their political opponents of being child abusers, so that might make sense for Google from a purely strategic perspective.
"But a kid seeing a nipple isn't illegal here"
"Doesn't matter, it's illegal in 'Merica, so to simplify things, it's now illegal wherever Google operates "
I guess it's payback for the EU cookies banners. /s