If not everything then at least all of the methods and classes.
I wish I new the history of this decision and more importantly what is keeping this artifact of the language in place. I suppose from a historical perspective it has not really caused any trouble. The language designers had some ideas that were rooted in commercial software and commercial software libraries. I’m remembering various commercial JDBC drivers, crypto drivers, X.25 drivers, MQ drivers. But in the modern development environment black box development is no longer the norm; so it might be time to change with the times.
Looking at Ruby, Perl, Python, even Groovy. They are all dynamic languages. They are all compiled or processed at runtime and so there is no benefit to private or protected objects. The code is there for the reading if you are so inclined. Java and C++ are compiled languages. Java does have some capability for runtime meta programming. But while historically developers purchased libraries to supplement the core JDK, they are now using Maven repositories like Ruby’s Gems, Python’s PyPi, and Perl’s CPAN.
private and protected are now more for vanity than any “protection” that the Java’s creators had envisioned.