The answer really is if you expect a measurable outcome from small-scale investing in people then don't do it, you're in the wrong space. If you view your investment as a path to the outcome you have in mind for them then don't do it, you're in the wrong space.
If you believe that a person deserves opportunity that might otherwise be blocked from them by what the privileged of us would consider incredibly low bars (money) and are willing to possibly not ever know if it made a difference or where that took them then it might be for you.