Nothing is wrong with not having children, if that is your choice.

If you want to start a family and are struggling to do so, that is very difficult to reconcile.

This is what I keep getting caught up on. I, for one, don't mind that my sperm count may be lower than my ancestors, or that my partners egg quality may be lower. I don't ever want to have children, so this honestly seems like a good thing to me. I know this isn't true for everyone (I'd say the majority of people _do_ want to reproduce), but for me personally, this kind of thing seems positive to indifferent at best.

this situation seems like an unhappy midpoint though. the chance of conception is still uncomfortably high for people who don't want children, while frustratingly low for those who do.

Hmm... I hadn't thought about it that way before. When you put it that way it makes more sense.

Well, they were actively deciding to and attempting to have children, for one.

Nothing, if you don’t want to have children.

But when you do, there’s a lot wrong with it.

Having children and passing on your genes is literally the entire reason you exist as a living breathing organism.

I wouldn't go so far as self-righteously telling someone what their purpose in life is. Besides that, if you want to go down that road, being in a support class and being a productive, supporting member of society in other ways is an evolutionarily valid position. Perhaps someone views their life's purpose to support close family, even if they can't have any kids, or their definition of family may be much more abstract and inclusive to a larger community. Perhaps they do what they do for humanity rather than for themselves alone.

Wouldn't raping and pillaging weaker communities be the most efficient way of succeeding at that?

As it had been for millennia before, I wager.