“Unsubscribe” is a two-edged sword. While it will stop spam from that particularly, annoying, email addy, the bot will still mark your email addy as being a valid email addy to be used or sold for future spammers.
I rarely ‘unsubscribe.’ I have my email program mark the sender’s email address as spam. After a while and when I think about it I simply delete the contents of the spam folder.
I've thought about that as well, except that sometimes expected or desired emails end up in that spam folder by a fluke, more often than I'd like. Then it just becomes the same problem as my main inbox: I have to sort through the junk anyway.
Ideally, 'unsubscribe' should stop the inflow from the outset. But I know we don't live in an ideal world.