I don’t like trying to guilt people into keeping a bird they don’t want fir whatever reason, as this usually leads to a bird stuck in a cage stuck in a back room or garage or outside sbd sbd given food and water but not much in the way of a life.....
But a bird that is so smart and social and has needs for physical activity being stuck in a cage. That’s going to lead to screaming and other less desirable behavior.. some birds won’t learn step up from a cage, but actually need to be worked with outside of the cage. Us humans are smart enough to come up with ways to do this, till the cage into a bed room, remove things that might get knocked over, set up perch areas , have a hand held perch, slowly work on shaping behavior in small segments, do this when you can take time to fool with getting them back in the cage we you are done. Also I think this species has need for burning off a lot of physical energy.
There are always ways to make things work, just like there are always excuses for why they don’t.
It does raise red flags that you took in another bird while you were and are dealing with a difficult burd situation... cockatoo are one of the more difficult species to meet the needs of sbd are often rehome because if that.... unfortunately Quaker’s are often re homes too because if the same reasons,, they to will act out and self destruct without plenty of attention activities and out of the cage time... truly Quaker’s are re homes in the thousands in my area , I myself have taken in two that didn’t fit in people’s lives, they are loud and can easily become screamers and pluckers due to them being extremely social smart and active species.... I do hope the Quaker is a better fit fir your household, and that you are able to meet his needs..
I hope the right placement for your cockatoo is found. And that you very actively share your experience and the difficulty with this species with others , especially others thinking of taking on this challenge. All species if parrots are nit easy pets... but some species have a much more difficult time dealing with the limits of captivity. People who are determined to have them, should be prepared to have the time and extra effort required to meet there needs, possibly including having an outdoor aviary fir them to spend some time in daily burning off energy.
Even my Quaker’s could benefit from an outdoor aviary, and I hope to make that happen. They are free flightier and out of their cage fir 8 hours a day.. but there are days I can see they need more.