Yes, of course the base systems root is necessary to create the jail, but then the jail has its own root user as well as its own /etc/passwd (and /etc/everythin

Yes, of course the base systems root is necessary to create the jail, but then the jail has its own root user as well as its own /etc/passwd (and /etc/everythingelse). For many, many purposes (almost all ?) a FreeBSD jail is indistinguishable to the root user from a bare metal server.