I can't speak for Devault, either, but I think that Sourcehut is intended to be selfhosted if you want. So it's probably too much pain to ask every language provider (might be a lot) to dial down the traffic. Imagine youre hosting modules from ~200 langs.
SMTP was first so one registered accounts with email and not XMPP. Companies send stuff like bills via email.
There were various popular providers -- today Gmail is the most popular one but others like AOL were popular before. It's hard to change one's address.
Sometimes, your ISP gives you an email address.
Email is formal, so job application happens also over email (at least in not very technical jobs).
Probably because email was so important, there were and are still more people who host themselves, including companies (companies with their own xmpp setup are rare).
The rest of email is today (mostly) at Facebook, Twitter or LinkedIn.
"They who have founded philanthropic institutions, such as no other country can boast of! Philanthropic institutions forsooth! As though you rendered the proletarians a service in first sucking out their very life-blood and then practising your self-complacent, Pharisaic philanthropy upon them, placing yourselves before the world as mighty benefactors of humanity when you give back to the plundered victims the hundredth part of what belongs to them! Charity which degrades him who gives more than him who takes; charity which treads the downtrodden still deeper in the dust, which demands that the degraded, the pariah cast out by society, shall first surrender the last that remains to him, his very claim to manhood, shall first beg for mercy before your mercy deigns to press, in the shape of an alms, the brand of degradation upon his brow."
Karl Marx
Google seems to like DNSSEC, otherwise they wouldn't have implemented it on their resolvers. Also, they have the best platform security team in the world, so who knows better than them?
DNSSEC is great, especially in combination with DANE, PGP, Email and arbitrary Email providers.
You can verify the connection between email servers and encrypt emails safely. DNSSEC seems to not be broken by criminals yet, and that's the most important thing.
I think you don't always get the latest stuff due to caching or so.