It's not uncommon for budgies/ parakeets to not want human interaction. Unless they are hand raised by humans it can be extremely difficult to hand tame them, and even then they can regress and not want anything to do with people.
It's just how they are, and likely how they were raised -- we are big predators and it goes against their instincts for prey to trust predator if they were raised by their parents.
You may just have to accept them as they are, and instead of trying to earn their trust and get them hand tame, turn your focus to making sure they are happy, healthy and have everything they need - fresh food and water daily, plenty of toys and a large cage to enjoy with each other.
I'm not saying its impossible to tame them, people do it, but it sometimes just doesn't happen... birds will be birds, flighty and content without humans whether we like it or not. My newest cockatiel was not hand fed and so is still frightful of humans moving too closely to her. She is much more comfortable with a bird companion in her cage rather then interacting with me, and that's okay.
If you want a tame baby, opt for a hand fed baby from a reputable breeder and keep it separate from the other birds so you can bond with it on its own.