If you’re using N+1 servers that have multiple users, then you definitely want some kind of centralized user management. It doesn’t matter how you connect to the server (ssh, etc). Those won’t solve the problem of keeping user account information in sync between the servers. You still need some way to keep account information (username, password, public keys) consistent between the servers.

That’s what the GP post was comparing to.

I use LDAP to manage access to multiple servers and it’s more work to setup than /etc/passwd, but much easier to keep things in sync.