Also I rarely have seen any government system installed in such a way that some kind of lawful intercept mechanism would be required to circumvent their interna

Also I rarely have seen any government system installed in such a way that some kind of lawful intercept mechanism would be required to circumvent their internal controls; they almost always are set up in standard boring enterprise way where an admin user can easily access anything, reset any credential, etc. I have seen systems where people forgot the admin credentials or lost access to the admins, but even in those systems there were easy backdoors with physical access. There are some systems designed to protect keys and admin access from lower tier admins (for crypto fill, etc), but with those they are generally not archival, just transport security, and there are ways to downgrade or replace keys on request. The judiciary also doesn’t in practice have any real ability to do things to the executive without cooperation of parts of the executive; if we had some insane civil war type situation where a federal judge wanted to enforce an order against the executive, it would be basically impossible to do so without some support of the executive (or an external force, like a state national guard). This isn’t how it should be, but probably was like this within a decade of the constitution’s ratification and has gotten more so with time.