When I first joined YouTube, you could upload a crappy video with distorted audio, totally pixelated, and expect to get a few hundred to a few thousand views. The viewership didn't just last a few hours, it was days, weeks, months. So it was fairly easy to actually get people to see your videos, pretty much if you posted, people would see it. But now, it seems like YouTube uses an ML-based system that does periodic checks on engagement rather than basing suggestions on the actual content.
