probably not a huge deal, but bigger implications

> Drop support for /etc/passwd and /etc/shadow

You say that as if it's a bad thing.

In the real world, requiring all processes performing authentication to (1) run as root and (2) work with plaintext credentials is both (i) a major security weakness (that has been exploited countless times) and (ii) severely limits the sorts of authentication mechanisms one can use.

> We're progressively but surely going away from the KISS principle that has made UNIX-based systems last 5 decades, and slowly turning them into a single megalith that nobody understands and that newcomers will denounce as the pest to combat like windows was pointed the finger at 25 years ago.

User info and authentication hasn't been obtained directly from /etc/passwd(etc) since Unix System V Release 4 in *1988*, instead proxying through the libc's NSS to allow for NIS and other directory services to be transparently used. This was later augmented by PAM (1996) and SSSD (mid-late 2000s), which in turn could be plugged into countless other user authentiction/directory services.

"KISS" ended nearly 40 years ago, out of the necessity of working in the real world.