EDIT: Replace Finn’s offscreen line to Poe about people rising up all over the galaxy with him saying, “Poe, I just lead a stormtrooper rebellion via hologram all over the galaxy. It was epic.”
Dang, that’s ironically all we needed to finish Finn’s arc in this movie. Not this line particularly lol but the concept itself. Imagine he beams out a hologram message for FO troops to rebel and that’s why we see the montage of FO Star Destroyers going down.
Would have been a better explanation than the sloppy “the people just did it”.