Many people think that reporting a subscription email as spam will cause the sender to take them off the list -- which is not the case.
All that generally does is to increment a counter in their email provider's anti-spam system. If a high enough percentage of recipients flag emails from a certain source as spam, their email provider will automatically block all posts sent to all users from that source -- and may report that info to Spamhaus and other public or private blacklist databases.
Now that most people read email on devices with phones and tablets that have small screens, they don't even see the "unsubscribe" link in an email unless they know to scroll down and find the link -- which is often in tiny, faint gray type on a gray background.
The "Unsubscribe" link in Groups.io is readily readable, which is good, but it is still off the screen for many users.
What if the "Unsubscribe" or "Your Subscription" link were duplicated at the start of each email?