Downtowns are always kind of dull and empty outside of work hours. They exist to house a temporary population of millions for 8 hours a day, 5 days a week; after those 8 hours, they are totally abandoned ghost towns because it's not like you can use office buildings for some other purpose at night.
Some cities are better at mixing commercial and residential real estate so you feel this effect less. Downtown Chicago always felt eerie to me on nights and weekends. Everything is just closed and there are very few people around. Manhattan is less like this. (There was a time when I would leave work between 11pm and 2am. The bike ride down 2nd Ave was always chaos. The city never sleeps.) I haven't spent a ton of time in San Francisco, but it strikes be as being closer to Chicago than Manhattan. After work, everyone is out in the neighborhoods.
In my non-expert opinion, people in California go to bed earlier than in New York. I feel like everyone thinks they need to be up for work at 5am to "beat the traffic" and be in the office for calls at 9am New York time. This means they are in bed 9pm. Meanwhile, you can stay out until midnight in New York and be sentient again for the same 9am call.
Some cities are better at mixing commercial and residential real estate so you feel this effect less. Downtown Chicago always felt eerie to me on nights and weekends. Everything is just closed and there are very few people around. Manhattan is less like this. (There was a time when I would leave work between 11pm and 2am. The bike ride down 2nd Ave was always chaos. The city never sleeps.) I haven't spent a ton of time in San Francisco, but it strikes be as being closer to Chicago than Manhattan. After work, everyone is out in the neighborhoods.
In my non-expert opinion, people in California go to bed earlier than in New York. I feel like everyone thinks they need to be up for work at 5am to "beat the traffic" and be in the office for calls at 9am New York time. This means they are in bed 9pm. Meanwhile, you can stay out until midnight in New York and be sentient again for the same 9am call.