Ibrahim's foundation launched its Index of African Governance (IIAG) on Wednesday, which warned that advances in human development and economic opportunities were undermined by worsening security and widespread democratic backsliding.
The study, which measured progress over the past decade on topics ranging from health and education to security and the rule of law, found that overall governance has flatlined since 2019.
Much of Africa, it said, is less safe, secure and democratic now than in 2012.
"Improvements in human development and economic foundations are undermined by an increasingly perilous security situation and widespread democratic backsliding," according to the 2022 Ibrahim Index of African Governance.
Tendencies have been reinforced by the struggle with external challenges such as the Covid pandemic and the climate crisis, it said.
"Governments have been increasingly prone to infringe on rights, curb freedom of expression and association, and impose restrictions on civic space," it said.
It said the trend "rapidly accelerated" when elections were cancelled in many places and governments used Covid as "an excuse to clamp down on dissent."
But the index said that more than 90 percent of the continent now live in a country where human development -- health, education, social protection and other criteria -- is higher than in 2012.
The five countries that performed best in good governance were Mauritius, Seychelles, Tunisia, Cape Verde and Botswana.
South Sudan was in last place behind Somalia and Eritrea.
It also said The Gambia, the Seychelles and some other countries were "bucking the continental trend," and cited broad improvement in the lot of women.
"In 42 African countries, women are seeing greater equality in political and socioeconomic spheres than they were in 2012," it said.
Ibrahim, who made his fortune in African telecommunications, said Africa was being swept up in a global authoritarian revival.
"We had 'Make America Great Again'. You have Turkey, Hungary, Russia, Syria, China. It's all around us," he said.
"We started to see coups, which we thought was something in the past. We started to see this phenomenon of the strongman ... It's something we need to fight back against."
Military officers have seized political control in countries including Mali, Guinea, Burkina Faso and Sudan. Traditional pressure in the form of sanctions and political isolation has largely failed to dislodge them.
While many of the external shocks crippling the continent economically and socially in recent years were outside of Africans' control, in an interview ahead of the report's release, Ibrahim lamented what he called "an own goal."
"We did not cause climate change, but we are hit by it. We did not start the war in Ukraine, but we're hit by that. We did not start COVID, but we get hit by that. Then we have bad governance. We're responsible for it," he said.
But Ibrahim said that, despite what he termed the current "sad place globally" for democratic values, he remained optimistic.
"I put my faith in the young people. Look at those young kids in Sudan," he said.
"For three years now they're in streets. They want democracy, freedom, things they've never experienced in their lives. When I see those guys, I have hope."
This report was compiled with data sourced from Reuters and Agence France-Presse.