There was also DIGG. There were several large aggregators, but they all made changes that lead to mass exoduses to reddit. Back in the day there were sites like SomethingAwful, EBaumsWorld that served up memes and entertainment before we had purpose-built aggregation tools. Eventually reddit will make way for something else (and already has to some degree with its shedding of users to Lemmy).
I never made a claim that Lemmy was even remotely comparable to reddit in size. Just stating that reddit users fled to here, when reddit made staggering changes affecting many.