Interesting, if you asked me to take a quick guess, I would assume that the repeated doubling would result in more than just 21 steps.
Anyway, my channel is less than 100 subscribers away from Stage 13, but based on how fast its sub-count has been growing for the last 4 days, I think it'll blow past that in the next 24-48 hours.
I don't know your channel, but try to re-evaluate the way you do things, from the video topics to the video structure, production, editing, scheduling and everything else that goes into this. Every time I go through the process of making a video and trying to get it to perform in this whack YT algorithm, it feels like trying to spin 7 million plates simultaneously, but if your current approach isn't yielding results you'd want, it's time for a change.
