As someone who lived in NYC for a while circa 1999 the process at the time as I recall it was using a newspaper classified ad to find a broker to find an apartment.

The vast majority of actual apartment listings were all gatekept within the broker system making hiring a broker (with an insane fee) effectively mandatory for actually finding a place to live in a reasonable timeframe.

What about the obituary?

Brokers still gatekeep the best inventory in NYC for the most part.

Every craigslist apartment I ever found was sketchy as hell.