Either this is categorically untrue (which, I'm inclined to believe) or I'm unhirable.

I know plenty of people in strong to very strong positions in google and was referred by one of them, yet did not get a job offer.

Among my collegues at L5-L6, we found it rare that anybody we referred was hired.

(I'm an Xoogler, and was there 2013-15)

The odds of anyone at the top of the hiring funnel getting an offer are really poor, but the odds for people with referrals are much higher.

The chances of getting a conversation with a recruiter and interview with a referral is almost 100%. But even after the initial interview, the odds of getting hired are tiny. That's the point I was trying to make.

Going through the interview process and just last week I was rejected from Google with a referral and without even getting a recruiter conversation. Caught me by surprise because with current education/work exp. I had no issue reaching the "talk to a human being" step with other FAANG companies... a bit disheartening but mainly just makes me wonder what Google is looking for at that point in the process that's different from other top companies.

Does something about this sound wrong to googlers?

No, all your referrals getting rejected is a running joke at Google. Often they get rejected even without an interview. In my opinion it is a bit evil to refer people who are unlikely to pass the interview, I always warn everyone I refer about it.

This is absolutely untrue. A referral doesn't hold much weight at all.

I had several pretty ranked insiders as references (one whose name you know), and it didn't seem to help me at all.