Once you unfollow every page, they'll start bombarding you with "suggested" posts from pages. There's no way to get away from them anymore. It's how they're able to sneak in their overwhelming amount of advertising.
Well, you can just stop using Facebook. This is basically what I’ve done, because I can’t stand the ridiculously low signal to noise ratio. 90% if the content on FB is content I have no interest in, and I am just not willing to wade through it to get to the parts I am.
Really.
Just stop. I haven’t been on Facebook in 10 years.