YouTube was known for being an absolutely squalid cesspool of low-effort right wing bullshit. Suddenly a bunch of media commentators started making well-made videos with various degrees of left-leaning politics, which was a very nice change. This happened during one of the various Bread Book revivals, so it was dubbed Breadtube, and lauded as the start of an important cultural movement. Later it turned out that most of it was one extended friend group worth of film students. Internet leftists, ever obsessed with labeling Thing Bad or Thing Good, continue to argue to this day over whether Bread Tube is good or bad, or whether the individuals in it are good or bad. Reddit, ever obsessed with chasing a thing that ran its course years ago, also has a community dedicated to declaring new things Bread Tube.