It appears that you want to use the term "far left" to mean something like "socialist". I agree that anarchists are socialists.

I don't agree that all Marxist-Leninists are authoritarian; and for what it's worth, I'm not aware of any Marxist-Leninist grassroots group operating here (UK).

I repeat: "far-left" is a term of abuse. It's routinely deployed by US persons of the Trumpian and Tea-Party persuasions against anyone they disagree with, including the leadership of the Democratic Party, a party that has never espoused any kind of socialism.