Probably if Africa had not been pillaged and looted, and its population of young and strong reduced to a nothing by slave merchants (population in some areas was reduced of 9/ 10), Africa will be in a better situation today.
Probably if Africa had not been devastated later by mono cultures of coffee and cocoa that destroyed the fertility of the ground forbidding any other food producing activity for many years, Africa will have been not so poor today.
Probably if African resources like tea in Ruanda or tobacco in Zimbabwe or oil in Nigeria and diamonds and phosphates had been left to Africa, some European countries (Belgium to make an example) and USA will be less developed and poorer today and Africa richer
If medicines had not been in the hands of few multinationals imposing high prices and patents IN ANY CASE, if our preachers had not insisted too much on no birth control and the condom as evil, if , finally, some producers of infant formula milk had not spent billions in advertising to promote formula instead of breast milk in countries where water is often so polluted to kill or leave disable forever many babies, Africa will have been stronger.
In this case, people of African descent will have preferred even more that their ancestors had not been forced to inhumane, humiliating and often deadly sacrifices to let their descendants live in a society that doesn't want yet them to grow in accordance with their potential.
All this did not happen so now they are glad to live in a country where they have 5.2 years life expectancy than the main ethnic group, an unemployment rate of 1 on 4 , where they are the "last hired and first fired" in accordance with your own government and , for the same job and job conditions are paid 30 percent less of their European descent colleague. Where 10 to 15 percent of their grand grand sons are in jail and where drug abuse follows strange ethnic paths.
Do they need to thank anybody?