Pretty much everyday is council day here - you can leave whatever you like, whenever you like, by the kerb and it'll be gone by lunchtime. While it's painful to see so much need, it's gratifying that everything finds a new home where it will be used.
[broken stuff is especially in demand - it can be fixed and reused - there's an active trade in collecting broken appliances. Large stuff, like furniture will be collected by charity organisations.]
I used to live in the SF bay area, and a good amount of items would be gone as you described. Items I couldnt sell on CL likely ended up on someone else's CL account who had more time to sell (I was moving) .
If I am putting stuff on the street, I try to trickle it out over the day, to spread the love, and hopefully avoid it all going to one person. The best is when it goes to someone who obviously needs it: perhaps a recent refugee immigrant, or a broke-arse single mum.
Picking up “valuable” stuff is a vice, so I try to only collect what is immediately useful to me or friends. It is however surprising the junk that people will take.
What they do, to extract $ value, is destroy use-value. The use-value didn't interest them, but waking at 4am and driving round before anyone ELSE sees the copper and takes it, interests them mightily. Consequently, anyone who is interested in finding things, finds broken things, not useful things.
I must have given a way over 50 items through this page. It is really nice that you can see the happiness of the person who will benefit from what you don't need anymore.