I don't know.
Written in Lynx through MLMYM web interface.

So the fediverse equivalent of rtv?

There's lem.el for Emacs.

There was another one but it doesn't work anymore. It hasn't been updated in 3 years.

I follow Lemmy's updates via newsboat (a rss terminal client), I don't need a specific CLI client. Besides, I use newsboat (together with Freshrss) to follow blogs and youtube channels updates. The latter, together with mpv, allows me to watch videos without visiting that data-stealing swamp, all without leaving the terminal.