That would continue to work fine with a default same origin allowance. A separate domain would require a referral policy.

Origin policy is a client thing. Referrer is accessible to the server. It's like using robots.txt vs. HTTP Auth to protect your content.

Referrer is also a client thing. Referrer based hotlink protection implicitly trusts the visitors' UAs. Same for Origin; it just offloads the actual check to the visitor. No big difference.

HTTP Auth, on the other hand, is actual password protection which cannot be spoofed by a malicious client. Very different from robots.txt.

This is just like traffic statistics - a help to the host, not the client. This is data sent voluntarily by the client so there has to be some direct benefit to the client in sending it, or at least sending any more than the domain name with out path, subdomain and parameters?

Also paywall skipping, to track what sites are bringing you traffic, to pass fields to forms to report problems, to present targeted traffic based on use, and of course, advertising.

The question was for reasons to __not__ remove them.

And those are all answers...?

How are those answers supposed to convince me to keep the referer setting in my browser on? In fact, they're even more likely to convince me to turn it off.

They want to know reasons why a user would want to keep the referrer, not the asshole that is tracking them.