My Opinion: Multiple YouTube Channels and When it Makes Sense
I think it is best to leave splitting up content among multiple channels as a last resort. There are more popular YouTubers than can do this because of their high level of engagement makes it easy for them to spread their audience among multiple channels and ensure that 80% of their subscriber base will follow them there. For the vast majority of YouTubers this is a bad idea.
A better idea would be to set up playlists for videos that fall into different segments. Besides keeping your audience on your channel, there will also be times you may have a video that you want to share with two different segments of your audience base and this way you don’t need to upload it twice and split the number of views and comments.
You may consider a new channel is if the content is just so different and unique that the audiences you are trying to attract are from two completely different groups. However, even though the better bet would be to try to find a way to create commonality among your viewers to keep them together on a single channel.
Question: When do you think is a good time to start a new YouTube channel?
Source: Multiple YouTube Channels: When Should You Create a New Channel?