Not sure where you took your "poetical exegesis" class, but you should ask for a refund.
The narrator as "vain, shallow individual" is entirely a character pulled out of your hindquarters, as there is nothing in the text of the poem to lead to that conclusion.
The poem is simply a reflection on how we, as individuals, make choices in life. Some of us choose to take the direction taken by most of those around us. That might be university, family, job, retirement in FL. Some of us choose to turn aside from that direction and try another path. Programming a PDP to play "Space Travel," for example. Or writing an operating system "just for fun."
Frost's suggestion is that these choices of path may seem insignificant at the time -- both paths being nearly the same; but that, as "way leads on to way," there's no going back and thus we may find ourselves down a path that leads to unexpected places. When Linus Torvalds wrote linux, he could not know that "the path less traveled" would lead to fame and fortune, literally. The college kids who created Slashdot could not know it would make them rich.
In fact, the point of the poem is exactly that it does matter which path you take. But that you don't always know how your choice is going to turn out. Frost himself might have continued his career as a teacher, a stable and certain means of supporting his family. Instead, he chose to focus on his poetry. He took a chance. And it worked well for him.