I did some (very) rough calculations on how much money you could have made. If you could have filled an entire box trailer with a cage on it with cans, you would have made around $274. For an awful lot of effort collecting, storing and transporting them.
(assumptions are that the trailer holds 2 cubic meters, and that the dead space around each can is equal to its volume)
It's definitely worth returning them. But collecting them on mass is a bit more marginal - it will be worth it for some people, but it's definitely not at the level that anyone should be kicking themselves for not keeping things in the past.