>"It's nuts and I can't believe it works."
The success rate is low, but the problem is that it's an arms race, where every competitor is spamming, so each new entrant (or non-spammer) must try to spam even harder to compete. If one elects not to spam, they are at a competitive disadvantage. If there is an anti-spam law or regulation, this just benefits competitors from other jurisdictions, where it is difficult to enforce the rule.
So then enforce the rule on the receiver side: people in your jurisdiction should have the right to be free from spam, and if you want to serve customers there, you need to comply. I'm pretty sure companies aren't going to opt out of the US market because if they're not allowed to send stupid marketing emails anymore.
>"So then enforce the rule on the receiver side: people in your jurisdiction should have the right to be free from spam, and if you want to serve customers there, you need to comply."
Every anti-spam regulation or law has this provision. The problem is that laws and regulations are rarely enforced, especially against people outside the jurisdiction which created the rule. Look at how infrequently GDPR is enforced outside the EU; it isn't even enforced rigorously against entities clearly violating it inside the EU!