Over the last couple of years I have had two vacations to the US and stayed in beachside communities.
Most recent visit - stayed in Carlsbad Village - clean, upscale quaint touristy town. No homeless in sight. Never saw a cart anywhere in a month, though there were some great 'set up' places - railway station, weekly village farmers market etc.
First visit - Oceanside - perfectly ok place to stay but definitely had a seedy side. A few homeless around, street drinking etc. I was tripping over carts. At one point I saw 3 within a few hundred metres of each other. One set up at the Farmer's Market every Thursday. Never saw them talking to anyone, Ignored the homeless, sat looking at their phones. (Pretty sure the homeless didn't want a relationship with Big J either). One was ALWAYS set up at the start of the pier. I talked to the guy a few times. Nice enough, but clearly bored, worn down, kind of gave off a dispirited vibe. But he was there every day.
I asked why so many carts together and he explained it was an 'intersection of territories' or something. More like poor management from higher up I say. What a waste.
And damn could they pack up those carts fast.