How does this guy grow so quickly im so confused

His last few videos are getting insane views. I'd be willing to bet that he's getting pushed by the algo on YT Homepage to a larger audience that enjoys a type of content similar to his. You can read the comments and see that sentiment. Tags, keywords and titles matter if you want to rank in search, but most of the views on YT come from recommendations on Homepage and through sidebars on other videos.

I don't think it's really possible to just copy someone and expect success. I've tried it myself and it didn't work. You have to develop your own style, see how people respond to it and keep improving over time.
I'd love to see such growth, but I think you shouldn't expect it anytime. Just do what you like to do and keep improving!
The only way I can see it.
People are engaging. (likes, comments, etc.) When you have a lot of interaction. YouTube promotes your channel, so your queued in a higher algorithm. YT only likes to see successful videos, once they see that happening. Promotion comes into play. I've been on YT for 4 years. Believe me. I got jacked up in the algorithm 7 times, just because 7 videos did well.