This is surprising to me, I’d say YouTube videos are harder to produce (and arguably consume) than blog posts. Does anyone know why are we seeing this trend? Is it because of monetization / easier to reach audience / something else?
On monetization it's not even close afaik. Some YouTubers make seven figures, and I don't know that blogging can get there. Although if some bloggers are making seven figures I'd be intrigued. Several YouTubers voluntarily discuss their numbers.
Keep in mind there are a lot of people who don't use a computer outside of work/school. For many people it might be a lot easier to lean their phone against something and hit record in the YouTube app than to type out a blog post
