It always starts small, sometimes even less than 5. Depending on your content, depending on your niche, depending on your approach, it will take a while to ramp up. It bears repeating that consistency is key in Youtube and that's still very much true. Going back to that niche, you should really stick with it when you have one as pivoting your content to something else can hurt you. It's the classic reason why Youtubers have seperate channels for other other content which doesn't fit into their main channel.