Are pellets or seed mixes better for pet parrots?

Across the specialist-community sources we read, the consensus strongly favors a pellet-based diet for pet parrots and cockatiels over all-seed mixes, which reviewers describe as fatty and nutritionally incomplete. High-trust r/parrots threads repeatedly note that avian vets recommend pellets like Harrison's, while seed-heavy products are positioned as treats rather than daily diets.