First of all, none of us understand matter or human bodies as fully as their Creator understands them.
Second, we see that Jesus’ perfect resurrected body bears His wounds. He does not need them for a purpose anymore (or so it would seem to us). But He bears them as an honor and trophy. And as far as anyone has said (and it would have been noticeable), He did not forsake His genitalia, any more than He gave up eating and drinking. (Which activities strongly imply that He also went to the latrine.)
(Unless He was processing the food in a way that left no waste - some scientists are trying to improve feed for livestock to a reduction of waste point, but of course it is a quixotic quest to think that there would be no waste unless you did something very different and sci-fi.)
There are many Biblical passages and passages from the Fathers which imply that in eternal life, parts of the body that have been used for good, will be sources of happiness and honor for us, just as those in Hell will suffer more shame about parts they misused. Hands, feet, and tongues are often mentioned, just as in Jesus’ warning in the Gospel; but the genitalia are not forgotten.
Also, the way you are talking seems to say that either lifelong virgins of either sex are somehow less human, or that parents are wasting their efforts. The Church has never taught either alternative. Neither has she taught that there are no differences whatsoever between male and female, or that one’s sex is not an important gift from God. God created those differences. He harmonized them, and He created ways that we are all the same as well as all different. But this is by Him being Our Peace, not by obliterating us as individuals who are male or female. One’s sex is both a physical and a spiritual gift, and it will persist for all eternity.
Our Lady is Our Mother, and her breasts are blessed forever. Do you think they will disappear, or that she will become an it? Of course not. Not to be a woman would lessen her.
Finally, it is often said that our bodies will not be just appendages in eternal life; they will achieve their final fulfillment and become what they were meant by God to be. So it seems likely that there will be non-sexual but useful functions for genitalia, or that we will find out what the sexes become when they grow up. It is fun to speculate about, but I doubt we will find out until it is time for it to happen.
I hope these thoughts helped!