The park feeder I go to has been running steady for decades. Generation upon generation of small birds grew up being hand fed by people who knew about the feeder and went by on a regular basis to keep them fed. But only in winter. I have gone to the feeder many times in summer and never saw a single bird. As soon as the first frost kills most of the bugs, the birds return, and stay until spring.
It only works because many people know of it, through published articles in the local newspapers, giving directions, and even from posts about it here in the bird forum. I do not think a single day goes by in cold season, that someone does not go by there and leave sunflower seeds, suet, peanuts, and bagged bird food, old pumpkins, bread, crackers, and anything a bird might eat. Those guys eat as good as some people. And the birds return the favor, by giving people huge smiles for the whole time they are there. I consider it a treasure.
But, "park bird feeder" is a misnomer. There is no real bird feeder there. Someone, in ages past, bolted an L bracket of 2x6's to the side of an oak tree and then put a trash can lid on it, upside down, to hold food up high where the deer can't get it. But now, food is put out on fallen logs, stumps, deer suet hung from broken branches, and just on the ground for the Juncos and birds who eat off the ground. But it wouldn't work unless lot's of people know of it and take the time to go by and leave food. As it turns out, it's mostly us old people, retired fuddy duddies with nothing else to do. It works, and it's a joy.
So you do not need to put up feeders. Just find a place easy to get to, in a car or van, near the road, and start putting food out. Spread the word, tell as many people as possible, tell them what your doing, show them where and once birds get tame enough to land in your hand, it should bring most of them back.