Updated April 5, 2020
The Federal Aviation Administration mandated that airports lacking long runways install sections made of a material* that stops planes when necessary (see 2 photos below).
The project at SFO began in 2014. The return to the full use of the affected runways was slowly implemented until the end of 2015. The change in fences, their locations, jet blast barriers (type and position), and "powerup" locations may have contributed to the current deleterious noise.
North Caroline, January 2010
Iran, January 2020
*Engineered Material Arresting System - In SFO's case, possibly 4-foot square blocks of crushable concrete aggregate filled with foam
Planes used to start their powerups close to here. x
Above image - date unknown
Before direct communications with the airport were determined to be futile, SFO repeatedly rejected my requests to talk with someone who was knowledgeable about the airport's runway changes.
Possible Explanation #1: Planes on the runways that face Oakland now start their "power up" (with the brakes on) 400 feet farther away from the Bayshore freeway before they start their "takeoff roll" (see photo above). The barriers that diverted the "back blast" noise up until the end of 2015/beginning of 2016 may have been replaced with a different back blast barrier that's no longer diverting the noise, or perhaps NO back blast barriers were re-instated since the jets now take off 400 feet away from the Bayshore.
The security barrier running along Bayshore Highway now
Possible Explanation #2:
Perhaps the side blast from the jets taking off on runways 1 and 28 no longer have an effective sound barrier between us and them?
Jets "side blast" on takeoff