My own sense is that the keeping of caged birds has a lot to do with the need for humans to feel they're in control of nature rather than part of it. A lot of birds establish their status by displaying fine feathers &/or songs with which they're born. Humans need to acquire things to display status. To acquire things they need to earn money which comes from the market place in both the broad & narrow senses. So while markets continue to pander to humans' need for status & control we'll see the demise of species of all kinds. Once these species have become extinct it'll be interesting to see what humans will then do to satisfy their control & status needs.
My own sense is that the keeping of caged birds has a lot to do with the need for humans to feel they're in control of nature rather than part of it. A lot of birds establish their status by displaying fine feathers &/or songs with which they're born. Humans need to acquire things to display status. To acquire things they need to earn money which comes from the market place in both the broad & narrow senses. So while markets continue to pander to humans' need for status & control we'll see the demise of species of all kinds. Once these species have become extinct it'll be interesting to see what humans will then do to satisfy their control & status needs.