I live in the Bay Area and this has not been my experience. Looking at Craigslist and Zillow the rents are stable. Perhaps the rate of increase has slowed down slightly. That is all.
This is not the case with single family homes for rent - as far as I can tell. The single family homes and in-law units are vanishing as fast as they ever have in the desirable areas.
I just left a place where the landlord wasn't able to find anyone to replace me with two months notice and a 20% reduction.
Lots of places aren't reducing the monthly rate outright, but are giving 1-2 months free. So a $3100 rate would actually be $2841 or $2583. This benefits them because it affects property valuation. There's other factors involved too, but this seems like the primary one.