At least in most of the EU these would be illegal. Privacy is taken seriously here and recording in public is not allowed unless you get explicit permission, like a film crew would need if they were filming a movie. Even outdoor security cameras need permits and/or agreements to be installed if they record public places or other peoples property.
Because of this it took over a decade for google street view to become available in Germany for example.
In practice these rules aren’t enforced for user installed dash cams, at least as far as I know, but I doubt any manufacturer would want to risk a direct confrontation with the law.