They are the questions that dictate how we are treated.
As a Cuban-American I have always questioned this lack of representation as well. As you may know, Hispanic culture is VERY diverse.
For Cubans our language comes from Spain, but our foods, traditions, and genealogy have deep African and Native roots. My relatives are Black, Brown, White, and whatever else you can think of. Yet somehow, we are expected to identify as White.
Why should I identify as such? Why should any of us? Are we to deny our culture? Our diversity?
Instead I would typically check the “other” box (if/when available) and write in “Cuban-American”. If there was no option I would leave it blank or just write it somewhere on the application. I always insist that my family do so as well. Representation fucking matters. Plain and simple.
Like you, this has always lead me to ask: Why is this neccesary? What’s the point? Which always points to racism. Our diverse cultures do not matter to those that ask, it only matters if we are, or are not, White.
It is, and always has been, what dictates how we are to be treated in any given situation.