That's not really true. I've lived in the Inner Sunset for 2 years, and I've actually noticed an increase in the local homeless population over that time. Obviously not concentrated/encamped in the way they are in the neighborhoods you mention, but still, they're much more present than in equivalent quiet residential neighborhoods I've lived in in NYC or Chicago.

Pac Heights is still great. So are most of the areas surrounding GG.

It varies. There were multiple encampments in the Richmond. 24th and Anza, 20th and Geary, and 16th and Geary for example. The city cleaned them up recently and posted signs about no lodging, but they were there for months before.