Can’t speak post Covid, but last time I checked they weren’t terribly impressive. IIRC the median was 1.1 years. Facebook usually tops the FAANG charts for retention, but the numbers still aren’t great.

Would love to see some actual numbers, even pre-COVID.

(The claim is at odds with my observational data... assuming, of course, that we exclude interns and similar.)

I'd like to know that too. Anecdotally, in the past 6 months 7 people I've previously worked with on projects at Google left after having been there about 10 years.

I don't know how good the data out there is but the meme seems to be that people are moving around a lot right now. Certainly I've seen a disproportionate number of long term employees I know deciding to either retire or switch jobs.