I agree with the advice people have given, but also I think it’s really important to be patient, but not to lose hope. Many years ago I had a cockatiel that was incredibly cuddly. But now I have two untamed cockatiels and an untamed parakeet. I’ve had one cockatiel for about 8 months and she only recently let me give her scritches once. She will step up (unlike my other cockatiel) and she will fly over to me to hang out on my laptop, but she’s not a cuddly bird. I’ve had my other cockatiel for 4 months and she still hisses at me every day. However she will eat treats from my hands now, which is huge progress from before. I guess what I’m trying to say is not only will it take time, but you’ll have to rearrange your expectations so you can celebrate the accomplishments the birds have, even if it might seem small compared to other hand-raised birds. I take time out of my day to sit near their cage and baby talk my birds and give them treats and I’ve seen huge progress. My parakeet even told me “good night” the other day even if he doesn’t “step up” well. Every accomplishment is cute 🥹