Then the complacency and other psychological effects that this article seeks to inoculate users against will be maximized.

Yes, the people who "subscribe" to costco are more loyal, etc.

But it also excludes. The general public is probably a lot more labor-intensive for costco, and they eliminate that.

If you ever need to use the service again just re-subscribe (and re-cancel)

In fact, what is stopping you from cancelling all your subscriptions right now? You can always buy back in when you like

Buy a domain. Get Proton, or Apple, or any other custom-domain email service.

Setup catch-all incoming mail.

Every merchant receives an email like merchantname@donotwriteto.me

Then you can either sort those out, or if they are malicious and not deleting you from your email lists, you can block the incoming traffic on that email.

This way you still can verify your email, comm stays private and you can have your own peace of mind, but you don't have to keep the spam in your primary inbox.