Gentrification didn't cause the vast expansion of homelessness in the 1970s and it didn't cause it in the last decade either. They were both caused by the same things.

1) a terrible healthcare system that neglects mental health problems and 2) zero income growth for 40 years due to massive dollar debasement over that time, which has eaten the poor alive (the rich can hedge a 80% decline in the value of the dollar since 1970, the poor cannot). The great recession - courtesy of the Fed's intentional asset bubble party - and the Bush dollar debasement (war, out of control spending & deficits), gave us the increase in poverty since 2006.

You mean the gentrification brought on by restrictive municipal zoning laws?

Palo Alto has 67,000 people. Mountain View has 78,000. Sunnyvale has 150,000. San Francisco has 860,000 and San Jose is over a million.

These companies are barely big enough to nudge the median income at all. Housing prices are being bid up, but it's not by residents.