You're sure doing your best to put forward a worst case scenario for avian ownership, aren't you.
Not avian ownership in general. Just the mass breeding and selling of large parrots.
Most people are too lazy to educate themselves about what is really required to keep these wild animals in captivity before they buy one. When most realize what they've gotten themselves into, either mistreat or neglect the animal for acting exactly like nature intended or they dump the bird off onto some other poor unsuspecting soul or at the local shelter who then has no choice but to send the bird along to a parrot rescue which is properly equipped to care for them.
The rescues are already overflowing with surrendered birds and there is no good reason to keep mass breeding and selling of thousands of new baby parrots every year.