I’ve been on both sides of this. I’ve apologized for things way too late, and also have gotten very late apologies. It has always ended well. Often times we need time and space to reflect on situations and get clarity.
One time apologized to a childhood friend after we had already gone to college for something I did to her in fourth grade. Turns out, she had been secretly holding it against me that entire time, but I had also been feeling bad about it the entire time. It totally transformed our relationship.
there’s a good possibility that you will continue to not have a relationship with that person, but it could provide a bit of feeling for you both to move on.
Editing to add that the person might not be ready to accept your apology, but that does not mean that you made the wrong choice.