Social movement scholar here. Earlier activists had petty beefs but those were wildly exploited by the FBI's COINTELPRO programs, particularly in the case of the Black Power movement. 1/
The successful nonviolence and civil rights movements of the past, as I’ve gathered from reading about them, ALSO featured a shit ton of incessant petty drama and in-fighting.
But crucially, they didn’t have social media - so this was kept far more private.