That is part of one side of the ledger, yes. But DDT is also has lots of direct negative health effects on humans: likely carcinogen (multiple types of cancer)

That is part of one side of the ledger, yes. But DDT is also has lots of direct negative health effects on humans: likely carcinogen (multiple types of cancer), can cause damage to the nervous system, hormonal+reproductive+developmental effects. Worth pointing out that there are multiple ways to fight mosquitos and malaria. DDT was only one.