useless is in the eye of the beholder.
The fact that you happen to work on a mailing list product does not change that reality.
If other people do and you are making me jump through hoops as a result to preserve your conversion rate, I'm reporting you to the relevant regulator.
> the unsubscribe mechanism is broken
Which one?
Are you saying some security solutions actually send a `List-Unsubscribe`/`List-Unsubscribe-Post` compliant HTTP POST with the correct payload, or do you think a URL in the email body is the gold standard of allowing people to unsubscribe?
Or are you just telling yourself that rationalization to avoid acknowledging that you're probably causing massive annoyance to many recipients?
I can believe someone, somewhere has insane security software that does stuff like that. But I don’t believe it’s common.