You can either collect them yourself, or pay somebody to do so for you, or you can BUY them from people who save them to sell to recyclers.
If I didn’t have anything much to do, I might advertise that I would be at a given location at a given time, on a regular schedule, and buy aluminum cans. The MORE you have, the HIGHER the price you can get for them. There’s an opportunity to make some money doing this, but not very much.
Anybody who has a considerable quantity on hand knows they are valuable, and will not give them away.