I agree for the most part, but I've still had lots of problems with them. I've found unsubscribe links that go to domains that don't resolve, or to pages that 500 or 404. I've hit unsubscribe pages where tapping the unsubscribe button doesn't actually do anything. I run into one of these once every few weeks or so.
Despite the requirement for a link in the email, of course they're going to put it at the bottom, using a smaller font, often with a font color that's closer to the background color. This is garbage. Instead we should have a standard for an email header that specifies how to unsubscribe, so that email clients can present their own unsubscribe button in a conspicuous place, and then unsubscribe the recipient without any extra interaction required. And if these links fail to work too many times, the email provider can use this as a signal to stop accepting mail from that sender entirely. (And we do have this standard header! It's called List-Unsubscribe-Post.)
But this still doesn't really go far enough. I want a full ban on sending me unsolicited marketing emails. Signing up for an account somewhere should not mean they're allowed to send me marketing emails, and any checkboxes authorizing that along the way should be initially unchecked. And they shouldn't be able to dark-pattern me into checking them by making it look like a required consent type checkbox.
Absent that, any entity that wants to market to me should have to send me an initial email confirming that I indeed want to receive their marketing emails. If I do not reply, that's considered lack of consent, and then they should not be able to try again, at all, forever.