The individual in the context of the vision was originally Michael the Archangel.
This is an apocalypse, and as such it is a “vision” or a scene in which the players are tropes borrowed from previous Jewish compositions, stories and writings to fit in with the Hasmonean narrative.
The Hasmoneans had just defeated the Seleucids and were now doing something the Jews had not done since before the Babylonian Exile, namely rule themselves with their own king. In the Book of Daniel, this is pictured with a series of visions, as if the events are settled via spirits in heaven. The idea came from the Jews being exposed to Persian ideas, especially their demonology and the concept that world events were thus destined to the outcome to the battles between the forces of good and evil.
While not named or necessarily Michael at the time of composition, at Joshua 5:13-15, before receiving dominion over Jericho (Joshua 6:2), Joshua only receives victory when the captain of God’s forces appears before him “like a son of man” in a vision.
The “son of man” is, sort of, “messianic,” only there was no messianic hope or theology at the time of its original writing. If that seems contradictory it is only because most are unaware of the evolution of Judaism and when and how the concept of the Messiah came about. It has a lot to do with the Hasmoneans.
When Judas Maccabeus led the Jews to victory against the Seleucid forces, that autonomous act of anointing and installing a new line of kings over the Jews led to a mixed history. There was freedom, yes, but the Hasmoneans abused it and their own people. They started to twist the Jewish religion in favor of the abusing Hasmonean rulers who engaged in forced conversions of those who were refusing to submit. Their own political intrigue, which included murder, blinded them to the rise of Rome, which was inducing the Herodians to trick its way into the Hasmonean line by way of its own subtleties. This was done by an arranged marriage.
When all was done, the Herodians had control of Judea, the Romans of the territory, and the Hasmoneans had nothing. The Jews were once again enslaved to new masters.
Always searching for answers in disbelief, the Jews turned to the Scriptures. The Mosaic Law, teaching that the kings must only come from the tribe of Judah, was claimed to be the sticking point. The Hasmoneans were all Levites. As the suffering under the Herodians and the Romans increased, a new theology stitching together texts where the promised coming Golden Age for humankind and the promises to David that one of his “anointed” offspring will always sit on his throne were developed into the Messiah theology of Judaism.
The Hasmoneans originally ended Daniel with the 12th chapter, where Michael “stands” and it spells doom for the Gentile nations but prosperity for the Jews. Oddly this did not happen this way. While the books of 1 & 2 Maccabees are quite accurate, historically speaking (even 2 Maccabees with all its religious references), due to the failure of that dynasty the books were never considered for the Jewish canon. The story of Chanukah that is celebrated is not the victory of Judas Maccabeus over the Seleucid army but of God miraculously supplying enough oil to light the Temple menorah for all 8 days of the first celebration of the re-dedication.
And the Book of Daniel itself? It is not even given prophet status. It is considered one of the Writings or Nevi’im. This was partially due to the fact that there was no “Daniel” who preached as a prophet to Israel or Judah (even in the book the character is not sent to prophesy to the Jews). The “prophet” is often considered a folk hero.
In the end, the great Jewish scholar Rashi who died in 1105 attributed the “son of man” of Daniel 7:13 to messianic expectations. So eventually, it has evolved to become that figure.
Today, many Jews do not believe that the concept of a Jewish monarchy that will rule all Jewish people and the world is compatible with justice. Therefore they do not believe in a “personal” messianic figure as part of the messianic hope.