plateau's are more common the smaller the channel, it's easier if your videos are sharable. You want that 80subs or whatever the number to be promoting your videos, and that only happens with certain ones.
If your a gamer for instance that does 50 parters. Why not also sprinkle in the odd one off? Like pick an obscure or old game and do one video on it where you just enjoy it, share your memories with it, or epic fail at it on an entertaining way. People are more likely to share that video with others since it's not a 50 part commitment.