has an outdoor aviary and it seems like her budgies are happy to interact with people, but the pictures usually do involve sprays of millet, so maybe it is at least somewhat food-driven.
My experience is that in some ways an aviary is just a bigger cage and in some ways it isn't.
As others have said, it's going to depend on the bird and the person.
Maybe an analogy is having a long-distance relationship with a person. There are plenty of instances of it working, but it's harder to maintain. If you've got a velcro bird I can't imagine that they'd say, "now that I've got all this freedom, I don't want to spend time with you anymore." A lot of times birds that are kept in aviaries are ones that aren't/don't want to be interactive with people, and being in an aviary means they mostly don't have to.
Going back to my own experience, my birds didn't come to me hand-tamed and they aren't of a species that tends to have tight bonds with people. And, I intentionally got two, knowing that would lessen their incentive to bond with me, because I wanted to make sure they weren't lonely when I'm not around.
I had made some progress towards getting them hand-tamed when I moved them into the aviary, and they did regress from that after the move. But, to be honest, some of that is just a reflection that I used to baby-sit them much more closely when they were out of the cage and I don't need to do that now. I kind of think if I made a commitment to go sit in their aviary for several hours a day they might start coming over to spend some time with me.
And, we are, in our own way, making progress. Mustrum has decided it's time to start training me. He comes over and holds onto the cage bars near where I sit, and I know that's my cue. They get their breakfast in stages, so if he comes over before I've served their seed course, that's his way of telling me they're ready for that. If they've already got their seeds, I bring in a few sunflower seeds or other treats. I expect he'll come up with a few other tricks he'd like me to learn - I hope he doesn't opt for "roll over" - getting up is hard on old knees.
But, for me, the important thing is that I know my birds are much happier and healthier living in a bigger enclosure. They're so much more active than they were before. They've got a whole ropes course they traverse. They do their swoopies throughout the day and they are also flying all the time to get from their seagrass hammock to the dining room table to the platform where they watch me work, to the top of their travel cage back to the dining room table. And, if someone's in a bit of a mood, the other one has plenty of room to just be somewhere else.
Of course, some people are able to give their birds that freedom because they've got things set up so that the bird can be out of the cage with their person/people most of the day. An aviary certainly isn't the only way to give your birds space.