> In both cases, the proof is the same: “email verification” means “the user controls an email address.” No. In one case the proof is "the user receives E-Mail

> In both cases, the proof is the same: “email verification” means “the user controls an email address.” No. In one case the proof is "the user receives E-Mails under this address" and in the other it is "the user can send E-Mails under this address". The service is generally interested in proving the first. For recovery, service-related notifications and for unsolicited marketing. So all the things mentioned in making the "normal" flow undesirable, are actually exactly what the service owner wants to protect against. If their E-Mails don't get to you because they end up in spam or just get dropped by a misconfigured Mailserver, they can't spam you and you won't be able to use this account for recovery. I agree that the reverse flow is easier (though TBF, mailto links also require the user to have set them up to work, which not all users have on all their devices). But I don't think that's where the incentives align.