I use Pocket also, but: For most web sites, Pocket makes a text-only copy that you can read offline without hitting the website again. But Pocket doesn't do that for Medium articles; it will only take you to medium.com to see the original (or offer to view it with the Medium app), so either way you have the login requirement, 3-article limit, etc.
I suspect that Pocket and Medium have some kind of agreement; Medium may have stepped in to say "you can't make that text-only offline copy; that's our content" and Pocket, not wanting to get sued, went with the linked strategy instead.
