In the US, I really think it's contingent on what state you are in. CPS's fostercare oversight is better in some than others. I believe the worst is New Jersey. They have actually
lost foster children in their system. In addition, they at one point outsourced their call center to India. (I shit you not. As if it was a tech support line.) People got wind of that and complained up and down, so they moved it back to NJ.
Those well meaning individuals that are not motivated by a cheque from the state every month.
I think they adopt.
You can foster with the intent to adopt, actually. It's much easier than trying to adopt outright. Also a lot of kids who are in the foster system aren't "needing" brand new, permanent, parents. Their mom could be in jail and their dad missing, for example. As such, they only need temporary care until their mom gets out of the joint.