We do. DDT has never been banned for disease control, it was banned for indiscriminate agricultural use and by that time resistance was already developing anyway.

Successful eradication in Florida and Italy was based on aggressive source control (stagnant water), control of re-importation, and use of insecticides (including DDT) for outbreak control.

Airborne spraying of more targeted larvicides continues to be used in Florida and other places.

Malaria rates in rural areas of Africa are much higher than urban areas so urbanisation also plays a role.