@jann vger is a particularly busy set of mailing lists, on a daily basis it will send literally millions of emails to individual addresses. Gmail has a lot of users, and thus we send a lot of email their way. Due to our volume, and our need for somewhat agressive retries, we can trip over the bulk sender limits very quickly. This then causes a cycle of more delivery attempts, because they've pushed back on accepting delivery, and our continuing incoming mail.
Recently the back log queue has exceeded 20K messages, noting that is messages not message + delivery email address so it's easily millions of messages + individual emails they weren't accepting.
All of this would be workable if there was a means to reach out, but that's particularly hard and slow with them. So yeah there's thousands of gmail users I can absolutely confirm haven't been getting vger related traffic because of the push backs and there's little from the vger end we can do about it.