This is why I love Apple's Hide My Email. I use it ALL the time and the unsubscribe button is always there. It's not the most polished interface, but it works perfectly.
Also, for any subscription for which I don't use HME, I will immediately "mark as spam" any minimally-spammy email I get. The ones described in the article would be insta-marked due to the lack of Unsubscribe button.
Firefox relay also good for this sort of thing.
And 1password which works fantastically with Fastmail with their Masked emails feature.
It’s fantastic, and also lets you track exactly who leaked your email.