What is the point of Moshe asking for a successor?

Question

Bamidbor 27, 15 &16

יִפְקֹ֣ד יְהוָ֔ה אֱלֹהֵ֥י הָרוּחֹ֖ת לְכָל־בָּשָׂ֑ר אִ֖ישׁ עַל־הָעֵדָֽה׃

“Let the LORD, Source of the breath of all flesh, appoint someone over the community"

Moshe understands that his end is near and so he asks HaShem to appoint a new leader.

Why does he do this? Moshe must have known that if a leader was necessary, then HaShem would appoint one and if not, what is the point of asking?

ADDED LATER:

When it comes to prayer for oneself, a similar question can be asked. But there is a difference. I have heard that the prayer for one's own needs, changes the person and hence HaShem can change the fate already arranged for him.

In this case, Moshe is not davenning for himself but for Klal Yisroel. Even if he is changed by this fine act, (the rest of) Klal Yisroel remains unchanged.

Answer 1

Because he planned to ask God that one of his sons should succeed him. The Midrash says:

Why did [Moses] make this request [to appoint a successor] [right] after ordering [that the women should inherit]? Simply this. When he saw that the daughters of Tzelaf'chad inherited the properties of their father, he thought, “This is the time for me to make my own request. If daughters inherit, it is [also] proper for my sons to inherit my glory.” [But] the Holy One, blessed be He, said to him, [quoting Proverbs]: He who tends a fig tree will enjoy its fruit. [Prov. 27:18] Your sons sat idly and were not involved with Torah [study]. It is [more] appropriate that Joshua, who served you, serve Israel and not lose his compensation. [Midrash Tanchuma, Pinchas 11]