Why don’t more people adopt?

So I know when it comes to financial reasons I can see adoption not being an option. If not, why don’t more people adopt?

I’ve recently became friends with a couple who had 7 kids. Literally all but one were fosters to adoption and they are literally the cutest family ever. They admit of course it comes with its own hardship especially since the main goal is to reunification of their original family. Even saying this, they look so much more happy and at just grateful than other traditional/bio families I know.

I’m not saying it’s easier in anyway, but there seems to be a fulfillment in giving back to a child in need and giving them a home either temporarily or permanently after some hardship. Why don’t more people ever consider fostering or adoption?