I’ve just done some quick browsing to see if there’s a written-down motivation for Referer existing, and there’s this on the Wikipedia: “Many blogs publish referrer information in order to link back to people who are linking to them, and hence broaden the conversation.”
Which I guess makes sense, in the context of the original use of HTTP as an academic publishing protocol, but it’s gained cruft and nefariousness since wider adoption came about.
There are good arguments for stripping Referer from the standard, and yours is one of the most cogent; if Referer is still a thing in another 30 years, I’d be surprised.