Then: You go to foxnews.com, then you go to pornhub.com. Based on hostnames we can make some inferences about you and your behaviors.
Now: You go to reddit.com(/thedonald), then you go to reddit.com(/twerkinggifs). Thanks to HTTPS, the specific subs you're visiting aren't visible to the ISP; all they can see is you going to reddit a bunch of times.
My ISP is welcome to know what sites I connect to because I pay them to do exactly that. Facebook and Google inserting their riders everywhere I go is not part of something I consent to.
And that's the root of the problem, if I send an envelope with my return address on the back the postal services have access to the meta-data and it is my decision to let them.
But it is not my decision to let a bunch of unrelated third parties use the contents of the letters to build up profiles on me and my counterparty.