I don’t know what anti-natalism is, but I think you can either create a baby or you can’t. Borrowing sperm from someone else and making a baby with it is some ant-like behavior imo.

Well your argument is valid, some people like and some don't. I think out of all the men who haven't even tried donating, a lot of them wouldn't have any problem with it but are just not bothering to look into it, and that's why I'm hoping i can remind those people about it. As for people who naturally find themselves opposed, I don't see any reason to proselytise - but I will practice discussing these points just for my own practice.

I don’t know what anti-natalism is, but I think you can either create a baby or you can’t. Borrowing sperm from someone else and making a baby with it is some ant-like behavior imo.

Interestingly, I figure this is also what the most-religious of people think, who ironically are pro-Natalist (pro birth and creation of more life); they oppose people getting pregnant if it is not on God's terms, and would rather people try to activate a miracle of fertility.

Borrowing sperm might seem gross and bug-like as you put it, however, we also borrow other peoples blood, plasma, stem cells, bone marrow, and body parts as big as bones and organs. And this is vital to people's survival. Now, people have argued sperm donation should only be done by private companies because it isn't life and death, and this is something thst was debated in places with universal healthcare - but healthcare is defined not by the saving of lives, but by the improvement and fulfillment of life through any means available. They are correcting a flaw with the function of someone's body when they do sperm donation.

to give sperm, I think it really matters that it will be used for things outside of your control,

I think it's a question of choosing where you donate. Admittedly, it looks grim for America, where all healthcare is privatised and USA sperm is known to be shipped over to cover shortages in Europe. For me, I made sure to pick my local NHS clinic, which also happens to be very well rated, and they're all covered by HFEA which is another international body regulating fertility stuff.

kids made from it will always be lost because they will be conflicted on their identity and who is their father

Regarding the identity thing, the reason that doesn't bother me is because people are born into that circumstance all the time - at least historically speaking. Peoples' parents die early, have to go to war, or people are conceived from one-time-flings and the parents lose contact before the mother even realises she is pregnant.

In my country, and i think all of Europe, sperm donation actually guarantees that the child can contact their biofather after 18 years. Parents can also tell them they were sperm conceived before that, if they want.

This does have the toss up of "who's my real dad?" But I think it's the same as having a step-~~father~~ parent, which is a situation plenty of people are in. Hopefully you love them both, in which case your mother's partner is your Step Parent, who you have a close bond with, and your bio father is your dad who was missing in action, lost in the Amazon, locked up in a POW camp for your entire childhood; they weren't around for you in childhood, but you get along and can have some relationship with them nonetheless.

That reminds me of something you didn't mention: It is also the only way for lesbian couples to get pregnant without engaging in PIV sex to get impregnated by strangers. Most people oppose this by saying they should adopt instead. There's benefit and fulfilment to creating a child that shares your own genes though, especially if you're someone who perhaps is keen on the continuation of your "bloodline"