Different parrot species have significantly different welfare requirements, with some (like budgerigars) being more manageable as pets than large species whose needs are extremely difficult to meet in captivity.
Parrot species welfare varies so dramatically that generalisation is unhelpful - a budgerigar and a hyacinth macaw have nothing in common from a welfare requirements perspective except their parrot taxonomy. Before acquiring any parrot, the species-specific welfare requirements must be honestly evaluated against what the owner can provide. Large macaws and cockatoos kept in domestic settings with insufficient space, social interaction and cognitive stimulation suffer chronically. Their long lifespan means this suffering continues for decades. Species-appropriate ownership requires matching the animal to the owner's capacity, not the owner's desire for a particular species. Rehoming older rescue parrots rather than purchasing young birds from breeders reduces demand and provides homes for already-suffering animals.