Nobody at Google making $200k has to share a two-bedroom apartment, even in the Bay Area. I was easily able to afford a $2000/month 1-bedroom in Mountain View in 2014 on a salary around $110k, and the same apartment today has only increased in price by 30%, whereas starting salaries have increased much more.

Is it more economical to share a 2-bedroom apartment when you're starting out? Of course, and many new grads share apartments both for money and, just as importantly, social benefits in a place where you might not know anyone else.