This is another personal anecdote, but I had an interview earlier this year for a database related role. The job ad had a huge salary range and the interview had nothing to do with the role. I wasn't asked any behavioral or technical questions. The two people on the call just wanted to get to know me. We probably spent several minutes talking about sports. A few days later I got rejected. What the hell?
Most likely a green card application related sham job posting where they already have someone working in that position on a work visa for several years with experience with their internals and doing a good job, but the regulations force the company to post their job at several places, interview people and reject them for some plausible reason, while applying for a green card for that person. All this needs to be documented properly.
It's extremely common at most companies, including MFAANG, because it makes zero sense to layoff the incumbent and hire a brand new person.
One of the reasons might be that you belong to a protected category (by gender, age, race, etc). These interviews are sometimes referred to as "compliance interviews". These candidates will be reported on the HR diversity metrics to prove that the company made an effort to reach out to diverse candidates (even though no actual effort was made). A few companies (Wells Fargo I believe was one) were fined by the Feds for these practices.
I've also been hired after similar "non-interviews". Sometimes it's hard to know if it's just disorganisation/incompetence or if there's outright fakery going on.
Perhaps a higher layer of management had a headcount target they wanted to fill for some reason, but this team didn't actually want or need new people but were forced to go through the process anyway.
