, you brought up a situation where some people are disabled. Lets explore that a second...
Categorically, biology recognizes "man and woman" as the procreational relationship. That is because 100% of reproduction happens between a man and a woman. Biology doesn't require all man and woman pairings in order to recognize what type of relationship creates children.
Exceptions are noted as disabilities. Infertility requires a reasonable expectation to be able to create children, including the acts between a man and a woman for a reasonable amount of time (like 3 years).
In biology and medicine, it is not a contradiction to say that infertility is (and only is) a procreational type relationship. It is a disabled procreational relationship.
So, the question is, do we deny people access to what they normally would be able to do if they weren't disabled?
Some societies don't, and infertility is a reason for annulment. Our society favors the support of the disabled, trying to restore everything we can for them.
One of the most regrettable conflations that I've seen in this debate is saying that homosexuality is a disability like infertility. I don't think homosexuality is a disability. Or on the other side of this is a denial that a disability is a meaningful distinction for our additional support, which I also find regrettable.
So in short, I don't claim any procreational relationship, even the handicapped, should be denied a marriage license.
The fact that they are missing out on a part of marriage is painfully evident to them, however. I won't prick an open wound. The billions they spend on infertility treatments and such, show just how much they miss it.
And it is because I regret their situation that I support giving them everything we can to restore as much as we can for them.