At least in the US, I think children are perceived as a nuisance right now, and adding special rules for them for airlines doesn't really change that. If anything it makes it worse. Some campaign like "don't get a dog, get a child" might have more appeal. E.g. one could point out how you can't bring a dog on a plane except in a carrier but a child gets their own seat.
Adopting a child is generally much harder than having your own. "Normal" kids rarely end up in foster or adoption situations. You see abused kids - you need a degree in psychology to help them recover from their background, or you see kids defects (genetic, mental, or otherwise) who need special care that is much harder than normal to give - while this could happen to you by random change, odds are it won't. Once in a while a "normal" kid has their family die (not just parents, extended family as well) and end up in the system, but this is rare. I'm glad for those parents who do take on foster kids, but it is not easy.
Adopting overseas is not a good answer - there is a lot of fraud (most countries will not even allow it anymore - it is too easy to kidnap a baby and by the time the rightful parents can get to authorities the baby is in a different country and impossible to trace down). There is still some opportunity, but make sure you are not unwittingly kidnapping a child.
That's certainly one of the issues - if having children was separate from raising them, like how pet breeders are generally not pet owners, children would be more of a fungible commodity and everything would be a lot simpler. I'm not saying it should be like that, just that economically it's one of the reasons the child business is not an efficient free market.
At least in the US, I think children are perceived as a nuisance right now, and adding special rules for them for airlines doesn't really change that. If anything it makes it worse. Some campaign like "don't get a dog, get a child" might have more appeal. E.g. one could point out how you can't bring a dog on a plane except in a carrier but a child gets their own seat.