I’ve never been in the Bay Area, but here you can make just above $100k and live comfortably with a <60 mins commute to work. I know that because that’s what I do.
You won’t be able to buy a house and having a kid without a spouse with a similar salary may be tough, but for a single person it lets you enjoy the city and actually be able to save money.
I don't doubt that someone can live in Manhattan on less than 30k per year -- my wife worked in nonprofit when we met and I saw lots of people she worked with managing to live in salaries that were half of what people on HN regularly decry as being effective poverty for the area. However, when you do a simple search for apartments for rent in Manhattan, studios are routinely around $2k/month.
I know! People should be satisfied with the opportunity to change the world (and make me rich) at my startup. Asking for more is kinda greedy. /s.