Final answer:
Afonso I criticized the Portuguese slave trade for taking high-status individuals from his kingdom, disrupting the social order, and violating ethical norms, despite his efforts to regulate or end the trade.
Step-by-step explanation:
According to Afonso I, the ruler of the Kongo kingdom, the trade with the Portuguese was problematic for several reasons. One major issue Afonso I highlighted was the aggressive and indiscriminate nature of the slave trading by the Portuguese, which ignored social norms and structures by taking individuals of high status within his society, such as relatives of the king and noblemen, instead of traditional sources of slaves like criminals and war captives.
This not only disrupted the social hierarchy but violated moral and ethical standards. Furthermore, the slave trade, particularly those slaves destined for sugar plantations in Brazil and São Tomé and Príncipe, was bolstered by the increasing European demand for sugar. Afonso I sought to regulate or end the slave trade and requested Portuguese assistance to develop his realm into a Christian state, but his efforts were largely ineffective against the economic interests propelling the transatlantic slave trade.