Milestone sounds like this one grew out of creator culture, where reaching six figures has been treated as a major turning point for a channel or profile. Rather than belonging to a show, film or viral clip, it is used as a flexible marker for the moment just before that threshold, when a creator wants to rally an audience. Its popularity comes from that shared understanding: viewers instantly recognise the number as a goal, not just a statistic, and the clip gives streamers, video makers and social posters a ready-made way to celebrate progress and encourage the final push.