I absolutely detest having to enter my email to unsubscribe. One click unsubscribes are the best. Thanks for opening this conversation.
There are some subtler anti patterns in this arena as well. For eg. exit interviews: Some of the unsubscribe pages make it look like you have to answer the survey to unsubscribe. But hitting the button without any answers will still unsub you. It is a cheeky way to nudge the user into providing a response. Which is understandable from a business perspective. But it it still a dark pattern.
The only other thing more annoying is a blank unstyled single line web page that says “You have been unsubscribed”. Terrible practice IMHO.