Well you can continue trying to make sense of his absence but it just boils down to the fact that he decided that he had better things to do than sticking around and looking after you. Please just consider that point. You were not only not a priority, but it doesn't even read like you were an occasional after thought to visit when it was convenient for him.
I do not state this opinion with any intent to make you feel bad. And I do hope that you aren't in some way blaming yourself for the sperm donor's lack of responsibility or decency. If you were a baby or low single digits of age when he left just how the hell could any reasonable person blame you for the scab's lack of love, decency or responsibility towards you?
My own biological sperm donor left about the time I turned four years old. The main reason we saw him just before I turned 15 was because my older brother told our mother that he wanted to see David, not because David had a change of heart. Various things happened between that time and when I went into the USN for four years at age 18 that convinced me that nothing had changed. I never told him that I was enlisting or going overseas and he never bothered to inquire about me so that he would know.
Fast forward to 2016, the year David turned 80. I saw him at my uncle's memorial service. He had lung cancer that was metastasizing. So about two years later my older brother and 17 years younger half sister decided that it was their job to instill a sense of filial responsibility in me to bond with David, presumably so he could get right with god or what ever. My sister's toddler like "But why? But why?" type refrains got annoying enough about the 3rd time I told her that we were done speaking. As for my older brother, about the second time he gave me crap for not feeling like traveling several hundred miles to see David before he died I let him know that that guilt attempt crap might work on his fellow believers but it was only pissing me off and would soon strain our relationship if he didn't knock it off.
David died in Summer of 2020 IIRC. In spite of entreaties from three siblings to consider attending his service, ostensibly so we could get a picture together of the five of us from his first marriage and the three from his second, I didn't bother.
I didn't get any satisfaction from his exit, but I didn't feel any loss either. He did stick around for his second batch and I give him credit for that. I am 23 years older than you are D'Andre. And I do have a dad, a guy my mother married when I was 13. So my situation is a bit different than yours.
Whether you elect to try to find that person, or write him off, or do something in between, please don't ever assign blame to the young child you were over 30 years ago for the donor's absence. It IS him, not you. To paraphrase a famous writer The fault, dear D'Andre, is not in you/ But in the donor, for he is a mere deadbeat.