Love this advice. It's also nicer for your audience, I think. Whenever I quit Medium for a few days or even weeks it's because I am bored with people re-writing their own articles over and over and over...just changing the title slightly and maybe a few different wordings. However I love Medium precisely because you can write about various topics and still be "successful" (whatever that means to you). I would imagine it's the same with Youtube. There are channels that are "huge" that don't have a super tight niche... .