The answer to this question is found in the earlier verses of Gen 32:
Then the man said, “Let me go, for it is daybreak.”
26 But Jacob replied, “I will not let you go unless you bless me.” 27 “What is your name?” the man asked. “Jacob,” he replied.
28 Then the man said, “Your name will no longer be Jacob, but Israel, because you have struggled with God and with men, and you have
Note the important transition - Jacob was a self-reliant person who deceived people for his own ends. BUT, when he glimpsed something of the person with whom he struggled (ie, God, vs 28), Jacob would not let his opponent go but held onto Him, begging for a divine blessing.
Jacob came away a different man: he went from self reliant, to dependent on God as symbolized by his crippled hip and needing help to walk. The change of name was also a reminder of this - we needs God's blessing constantly.
Note Barnes comments on Gen 32:28 -
"What is thy name?" He reminds him of his former self, Jacob, the
supplanter, the self-reliant, self-seeking. But now he is disabled,
dependent on another, and seeking a blessing from another, and for all
others as well as himself. No more Jacob shall thy name be called, but
Israel - a prince of God, in God, with God. In a personal conflict,
depending on thyself, thou wert no match for God. But in prayer,
depending on another, thou hast prevailed with God and with men. The
new name is indicative of the new nature which has now come to its
perfection of development in Jacob. ...
Disclose to me thy nature. This mysterious Being intimates by his
reply that Jacob was to learn his nature, so far as he yet required to
know it, from the event that had just occurred; and he was well
acquainted with his name. And he blessed him there. He had the power
of disabling the self-sufficient creature, of upholding that creature
when unable to stand, of answering prayer, of conferring a new name,
with a new phase of spiritual life, and of blessing with a physical
renovation, and with spiritual capacity for being a blessing to
mankind. After all this, Jacob could not any longer doubt who he was.
There are, then, three acts in this dramatic scene: first, Jacob
wrestling with the Omnipresent in the form of a man, in which he is
signally defeated; second, Jacob importunately supplicating Yahweh, in
which he prevails as a prince of God; third, Jacob receiving the
blessing of a new name, a new development of spiritual life, and a new
capacity for bodily action.