"Truthfully, I didn't realize how much I've missed working side by side with Dick. We have a shorthand I don't share with any of the others, save for maybe Alfred. He's always been the one keeping me centered. Grounded."
I genuinely don't think Bruce has a favorite among his sons, I don't think that's what this is about. He has a unique relationship with each of them and each of them are narratively a reflection of a different aspect of Bruce, each of them occupies their own space that's not about the others.
But, and admittedly I may well be biased because of who my favorite is, I do think Dick was the first and that means something. Because he was the one that broke down the wall first and because it had to be him that broke down that wall, the way his tragic loss mirrors Bruce's and the way Dick is a narrative counterweight to Bruce, that Dick amongst all of them, is the overall superhero that Bruce wants to see in the world. He's the light that Bruce wants to see, even while he works in the dark. He's the one who refuses to not be loved, time and again. Respected, yes. But also Dick demands to be loved.
That this is what keeps Bruce centered. That being poked and prodded to keep acknowledging that he loves people and that his presence in their lives helps them, that's what grounds him. That's reflected in Dick's big speech in this issue, that Thomas and Martha disapprove of Batman because they haven't yet seen what Bruce did for these kids he loves, what he did for Dick's life.
And, too, I think Dick was the youngest when he came to Bruce and the one Bruce raised the most, that Dick will always be his boy in a way the others were already halfway to adulthood, that Bruce loves all of them just as much as each other, but Dick will always be his kid. It's why he struggles over and over with respecting Dick's independence and autonomy, because that right there is his baby even more than the others, who came to him later and more independent.
Bruce has unique, complicated, and fascinating relationships with each of his sons, so much depends on who needs him the most, that's who gets the priority and the interaction and narrative weight at the moment. But when you ask which one of them does Bruce need the most--it's the one who understands him and centers him, the one who still looks at him, this complicated and flawed and often broken man of a father, and says, no, you're going to love me.
Because that's what Bruce needs more than anything, that's when Bruce is at his most interesting as a character, when he's interacting with those he loves and being forced to reckon with all his issues because he needs to be better for them.