Mainly because most good jobs in Silicon Valley are occupied by foreign workers.
Young Americans in San Jose can’t get jobs there because they are all occupied.
Didn’t foreign workers promise to create lots of good jobs for everyone?
If that is the case then why is there even any homelessness in San Jose at all?
sanjosespotlight.com/san-jose-the-no-1-u-s-city-in-youth-homelessness/

