No, I meant that Windows AD was still the answer two decades ago. I can see how that may not have been clear - I edited my post to include the quote I was replying to. (You said one decade and I was just extending that timeline back another 10 years.)

There was LDAP and Kerberos support for *nix management, but nothing you’d deploy over a thousand end devices.

And you’re right, it wasn’t a question that got asked, because there wasn’t ever a second choice - AD was the only option.