Two of my first ducks were Pekins that were bought as Easter ducklings for someones grandchildren, then released onto a large river near Annapolis Maryland that feeds into the Chesapeake Bay. I heard about them and their history through the grapevine so there was no doubt that it was OK to re-home them. Sal and Midge took immediately to my Pekin at home named Pong, whose made had just died suddenly (no warning signs, no apparent injuries or attacks as she was just dead in her secure duck house one morning). They were all only 2-3 months old.They instantly became best friends and still always hang out together, even though I've got a whole bunch of other ducks this past year. They have a fenced in area next to my house that barely totals a quarter acre, with their pen, trees, stone walls, my patio and the remains of my flowers and a couple of kiddie pools. I can't get inside their heads, but they seem to be the picture of contentment, lounging in the shade, rooting around for creepy crawlies or eating my flowers. I wonder if they miss their big river, especially when it's muddy out and they don't get fully clean, or if it's icy in their pools. But I don't know if ducks think like that. It is highly unlikely anything would get them from the ground during the day because of the fenced yard, nor at night because of the secure pen. Every night they go in the pen themselves but do complain if I send them too early. Overhead predators are a bit of a concern during the day but they ducks have a good eye on the sky, better than any of my roos or other animals, and will run into the pen if they don't like what they see. They never go hungry and they get lots of ducky treats. I give them medical treatment if they are hurt or ill (knock on wood only very minor things so far). Ducks are a fun loving bunch.
I think it's a good life for a duck and keep in mind, these birds are domestic animals, not wild ones. You don't need to feel bad about ensuring they get a safer place. Certainly make sure you're not taking anyone's bird. Unfortunately if other people don't want to do more for their animals, there's not much you can do besides trying to talk to them diplomatically.