There are gigs on the Penninsula. Might as well be living in LA though. You drive to everything. Traffic is nuts. Biking puts your life and sanity at constant risk. Few areas have any charm to them, and none of those are remotely affordable. San Jose / Santa Clara proper are, apologies, pits.
San Francisco is walkable, has street life, functioning transit (well, for low values of "functioning"), is not strictly a tech ghetto in the way the Penninsula / South Bay are, and beats the heat in the summer (temps ~15-27C rather than 27 - 41C). You can walk to bars, clubs, museums, talks, art shows, or a gym after work, or reach it quickly on transit. When Muni breaks down, you can reasonably walk home.
Yes, housing cost per square foot is higher than elsewhere. That's what density means.