Earlier quoted context omitted.
Just a perspective from the other side of the coin: I host various services for schools like online registration for parent - teacher conferences. When the platform is live hundreds of parents are logging in, choosing their appointments and have to confirm them via email (only one email per person not per appointment) And Yahoo is the Single worst email service to send to. I have correctly configured sfp, dmarc, dkim…
I seriously don't get why we can't have some sort of licensing authority for this type of thing. Maybe they issue you a secret key to include in email headers, or put your entire domain on some sort of whitelist. And complaints get handled by a human to confirm that it's not a "oh I don't like this, or I don't remember signing up for this" non-sense complaint that would get you blocked or have your license revoked wi…
You'd also have to do a lot of work to validate new senders long before they send their first message and you start getting complaints or else you're just letting spammers pay you to completely bypass every mail provider's spam filters until they finally get blocked and have to create a new account with you under a different company name.
If you can convince everyone to trust you, and your service, and that it'd be worth it for mail providers to do all that work on their end on top of everything they're doing currently to prevent spam, it really could improve deliverability.