A low IQ black population that murdered all the whites crippled Haiti.
Haiti is a cultural failure. No guiding concepts that would provide the structure needed for stability. No functioning court system. No tradition of property or contract. No way for people to gain a title to the housing they have. Hence no way to mortgage and raise capital. No matter how much aid is invested, Haiti is just a car without an engine. You can give it a paint job and buff it up but it’s still going nowhere fast.
If we lived in an even remotely rational world, the UN would assign a national guardian, probably France would be a good choice, since they used to have it as a colony. Take over governance, provide the muscle to subdue the gang mentality by whatever means necessary. Run the place for about fifty years until the people figured out how to run it themselves.