Spammers don’t tend to operate from first-world jurisdictions. (When they do, CAN-SPAM is decent about requiring working unsubscribe buttons). Spam is not a problem you can solve with regulation.
Sure, I don’t expect to stop receiving invitations to enlarge my genitals in my spam folder because of GDPR, but I’ll be happy enough if it discourages dodgy online shops and growth-hacky startups from automatically signing me up to their mailing list because I made a one-off transaction and “consented” to receive their special offers for all eternity on page 25 of their terms and conditions.
Oh, I wouldn't expect it to solve the spam problem. But as I said, there are a lot of US-based companies that are at best sloppy with address management. Those are also the ones most likely to make it past my existing filters, because they are semi-legitimate. Being able to turn up the heat on them would be a pleasure.
Mostly true, but I would say that - while regulation certainly shouldn't be the primary tool used to fight spam, it can help discourage bad behavior within a jurisdiction, and can reduce spam load a bit. Mostly by secondary effects (e.g., an email service provider says to their customers, "here's the legal standard, we need you to adhere to this").
No, that annoys me the most, that I have to go and click the unsubscribe button and wait for the page to load and then click another button. They should have not sent me the email in the first place.
Most of promotional email I get is from local businesses operating in my own town. And each time I unsubscribe it feels like my email gets handed over to the next mailing list of a similar business. Recurring topic is "art galleries" and "event venues". I'm pretty sure GDPR can help with that. And, also, possibly related to GDPR: I already got couple emails asking to confirm I want to continue receiving emails. Chances are this is related to building the verified opt-in list this article mentions.
The first is already illegal, and yes, it's difficult to fight and comes from first world jurisdictions.
But the second is operated by well known companies, most of the time through well known service providers (Salesforce, Adobe...). And these companies do put a lot of personal information in their databases (what did you buy, did you click on a specific link, did you open a specific email, etc).