You also threw a nasty insult at the person, instead of conversing in good faith.
What's artificial about housing demand growth due to immigration is that they arrive into the market as adults. The natural demand growth would in contrast be from births.
The foreign-born population of LA and SF hasn't changed significantly in decades. It was like 27% in LA in the 80s. Housing there is expensive because there's a lot of demand from a lot of people. Immigration is like reason 11 out of 10 for why housing is expensive in those areas.