ssh was created in 1995 by a Finnish university researcher at the University of Helsinki, his name is Tatu Ylönen :)

Likewise, IRC was also created by a fellow finn back in 1988, Jarkko "Wiz" Oikarinen, at the University of Oulu.

In 1997, SSH was relatively new, a couple years old (looked it up).

It did spread very quickly, as the issue it solves was quite obvious and there weren't a lot of competing solutions. So it's pretty possible that that was the actual tech used.

In my experience, it wasn't until 2003ish that telnet really started getting replaced by SSH, with telnet access being routinely shut down. My memory is really more around dev environments, prod envs may have been a lot more locked down.

In the late 90s I used telnet to a unit machine of some sort to manage my websites. In 2000 I went to uni and we were told to use rlogin!