Are blogs dead? Well, if you're reading this on a blog, then... no. No they're not.
A few years ago every website and social media personality having a blog was all the rage. It was "the thing". But the hype did die off over the years. That's why people now say blogs are dead.
But that's not true.
Unless you are a full time blogger, they're not the big "in style" thing they used to be, but people still read blogs. Blogs will still help people find your website. People will still seek out blogs for information.
Many people would argue that video content is superior, but not everyone learns from video best. Some people learn best by reading. Not everyone enjoys videos. Some people enjoy reading more.
There is no 'one size fits all'.
So no, blogs are not dead.