Depends on the kind of writer or blogger.

Like for example for some successful bloggers, here's a link: http://getoffmyinternets.net/how-much-do-bloggers-really-earn/

For successful writers, they can make even loads of money if their best selling book gets to turn into a movie. Then from there selling merchandises. So you could look into getting 7 figures but it will take a really long long time to get there.

In conclusion, Writers make more money in the longest run. But Bloggers can make money sooner than writers. But if you put them together, you'll be a hybrid in the writer's world.