As someone who knows several people who wanted to adopt - it's not as easy as you might think (at least unless you are able to spend a lot of money adopting children from abroad).

Adopting older kids who come from problematic backgrounds has a significant probability of them having experienced some sort of trauma before they got to you. It's absolutely a great thing to do to take care of these kids but potentially very difficult as well.

This is why it's very difficult to get to adopt babies - they are the ones that everyone wants. Not saying this should make anyone not adopt just that it's not as easy as you seem to think - western countries actually don't have that many orphans & a lot of people who want to adopt them (which is of course a good thing!).