There are two kinds of deviations on the left, right-deviations (aka opportunists) that are succdems and such, basically defending capitalism and always siding with libs against communists, and the left-deviations (also called ultras, leftcoms etc. often including anarchism) who refuse to acknowledge every real-world attempt at socialism as "not real communism", "statism", "authoritarianism", "state capitalism" etc. because real world has a habit of clashing with their ideals.
Some short reading.

If you want to met those latter people, probably just wait for the answers for my comment here, since there's many of them here on fediverse.