Along those same lines the “born this way” theory of homosexuality (as put forth by Dean Hamer) has been falling apart lately. It might be true for a small percentage of men but it cannot be strongly correlated for women or for people who are het-gender. And there is a growing consensus (see work by Joanna Wuest) that medicalizing LGBTQ+ is counter-productive to the goal of equality. (For much the same reason that there is a push to de-pathologize autism—medicalization reifies inequality.)
I actually tend to agree with this - in general, human sexuality is a combination of biology and environment. They've identified genetic anomalies in homosexual men that have to do with olfactory discrepancies between straight vs gay men. So there are some genetic factors at play for sure, and it would also explain why there are homosexual animals other than humans - animals generally have a much less developed comprehension of the environmental factors that influence homosexuality - yet they are still homosexual.
But I also agree that environment influences sexuality because as far as I understand it, it is actually very rare for a human to be "all gay" or "all straight" and most of us fall somewhere in-between, but it's society and culture that pushes us to identify strongly as one or the other. (And particularly amongst men, I know there's a large subset of men who have sex with other men who still consider themselves straight, and view this sexual activity as something very simple and baser. So are they gay, or just blowing off steam?)
However, I would encourage caution on categorizing pedophilia in the same vein as heterosexuality or homosexuality. Pedophilia is a neurodivergence, the only reason it is related to sexuality is because it affects sexual behaviors - but largely I would not classify pedophilia as a sexual orientation. It is a paraphilia, the same as how we don't classify rapists or rape fetishists as having a "rape sexual orientation." Rape and pedophilia are harmful behaviors, and they cause distress both in the victims and often in the perpetrators as well.
And it is also this that is rooted in deep homophobia I believe, as the correlation between "pedophilia" and "homosexuality" has always been exceedingly strong. Even today people shout "groomer" at transgender and gay individuals, associating them with child abusers. So personally I work to distance these terms as much as possible, since they are describing two very different human behaviors. One is normal, healthy, and should be encouraged and celebrated and ordinary. The other is harmful, distressing, destructive, violent and hostile.