Your browser renders the page by means of making a copy, which requires a license to you. Usually this is granted by the website. It has been argued in some places that this includes a right to control the "integrity of the presentation", that is that you're not licensed to display the page if you block ads.
For the average reader, there is no difference between medium, google cache, rss reader, archive.is, screenshot, pdf, getpocket.com, copy pasted snippet or printed pages of the same article. In that sense, medium means nothing. Just some meaningless wheel in the whole system, annoying us with their ads. We owe them nothing. Medium is blogger is livejournal is a column in a newspaper is private subreddit is google+ is everything2 is svbtle is obtvse is wordpress is textfiles is github pages is a mailing list is paper.
People ignore it takes some effort to "publish" content. The dissemination of said content is such that we don't really respect, at all, these "publishers".
I don't really have a point, am just slightly annoyed to be reminded such plumbing is, in fact, a business model.
If we want to continue with newspaper stand analogies, Medium would be like a newspaper stand that has one copy of each newspaper and magazine it distributes, and has a photocopier. When a customer wants a copy, that newsstand uses the photocopier to make one for them.
Firefox is a tool you use. People (incl. companies) need licenses, not tools. And yes, you do get a license to download the content for the purpose of viewing it.
Internetting is hard.