There are at least two reasons why the scramble for Africa is historically significant.
First, the competition for colonies in Africa can be cited as a cause of WWI. The various European countries were competing for colonies and for power. They felt that having African colonies helped them economically (which brings military power with it) and that it helped to give them international prestige. Because of this, they all wanted more colonies. Germany, for example, tried to gain influence over French colonies in Africa. These sorts of actions made countries like France and England nervous and helped lead to the war.
Second, the Scramble for Africa can be blamed for many of Africa's problems today. Essentially all of Africa was colonized. The colonizing powers set up economic systems that were meant to help the colonizers, not the Africans. They did not do much to educate the colonized people or get them ready for independence. They put different ethnic groups together in single colonies. All of these things caused major problems when African countries became independent in the 1960s and 1970s. The colonial systems made it so that the African countries had poor economies and chaotic governmental systems. Thus, you can argue that the Scramble for Africa helped made African countries some of the poorest in the world today.
The scramble for Africa or race for Africa marked the beginning of radical changes in Africa and the start of colonization on the continent. The entry of countries such as Germany, Italy, and Belgium in search of resources and territorial expansion led to the need to develop boundaries in Africa to reduce conflict between the colonizers.
The boundaries established during the Berlin conference formed the national boundaries of African countries after independence. Some of the ethnic groups settled along border lines were divided and forced to be nationals of different countries despite their shared ethnicity. The situation led to civil wars between different groups and increasing administrative challenges, some of which are experienced still today.
The scramble for Africa also led to attempts at colonization in other parts of the globe. The European Imperialists made attempts to carve up China and succeeded in taking over some Asian territories.