> Perhaps part of the reason is the massive wealth gap between the tech migrants (tech workers) and the local population. It causes a lot of friction between locals and the new migrants. The lower earners are being forced out of the city and they probably make a up a large chunk of the service workers.

The current disparity certainly causes plenty of concerning issues, though SF's early closing has been a thing since at least 2007 when I first lived there, at which point cost of living was somewhat reasonable.