Phishing Protection at the DNS Level. Comparing DNS-Based Security Filters
medium.com
medium.com
It would mean a massive overhead in DNS queries (as opposed to passing the link on to the frontend) for a large site, but wouldn't this be something a DNS caching could easily handle?
While this wouldn't do anything to reduce actual spear phishing by email, it would reduce the possibility of spreading links widely on big social media sites.
I'm probably missing something though because sure others would have thought about such an obvious thing and turn it into a feature.
Edit: I forgot that you'd also have the overhead parsing the link so it's not just extra DNS. still ...
There are multiple phishing blacklists that any provider can leverage.