throughout my life, I have been good friends with teenagers and younger simply because I'm visibly queer and trans, and they were queer. That's not a weird relationship, that's a "holy fuck, there are other people like me".
An 8 year old considered me her best friend after I met her at a toys 'r us when her mom slapped her, and i confronted her mom about it. I was the only person she talked to about the parental abuse for a while until she felt confident enough to tell others. I gave her a copy of my house key in case she ever needed it. (she hasn't. Her dad's in prison now and her mom is . . . better enough that she's forgiven her)
I run TTRPGs and regularly make friends that way. Some of them are 80, some of them are 12, we all bond over being omnipotent magical frogs for a while.
I'm a known eccentric at my local nerd conventions. I've checked in on younguns' who I notice are seeming overwhelmed, or are sitting by themselves away from their friends, and sometimes they tell me all their life troubles and about their depression or anxiety or whatnot and I'm able to give them my perspective . . . which is helpful sometimes.
I run a YouTube channel reaching people how to make custom content for a specific videogame series, and most of the people I interact with there are teenagers, (they have the most free time to do such things).
I bike everywhere, and I'm often seen repairing my bike on the sidewalk outside my apartment, so the neighbourhood kids will often cluster around me getting me to fix or tweak their bikes for them.
I've known my friends' son since he was born, and I've tutored him in math from grade 1 to 3rd year university. He joined my fencing club for a while, he's been in and out of my boardgames groups.
My friend's daughter is the weirdest little gothic drama queen autistic 13 year old, and we hang out and watch anime together. I show her classics like cowboy Bebop and talk about the influences they've hard on anime since then, and she shows me recent stuff like Frieren and we get to discuss how awareness and familiarity of fantasy tropes has evolved to allow such storylines.
Like, there's nothing predatory about generation-gap friendships, (and the weird thing about them is only that it's less likely to happen so it sticks out), and ergo a best friendship isn't predatory either.
I can't imagine refusing to bond with or help someone over age. I can imagine not liking someone because they're a horrible brat, but that's age-independant. I don't generally enjoy being around kids, and they tend to remind me of my childhood traumas and trigger me by being kids. But like, that's not a them problem.
Perhaps the big question is: if you think it's predatory, or even just weird, why do you interact with children so little that you aren't familiar with intergenerational friendships?