I think there is also a big difference between our caged/housed birds and the wild birds- wild birds have no human interference so they learn all the important and pre learned stuff from their parent birds but the birds we humans breed and tame are interfered with from often as early as the owners can force themselves into the picture which means all our pet birds have much less information passed onto them from parents. We often find many issues of pica, plucking, impactions etc in pet birds whereas we do not hear of see of these problems in wild birds.
My point is that we can not really say that birds have lived successfully for thousands of years without problems and line that up with our pet birds as our pet birds are nothing like their wild cousins.