And those prone to walking a circle around what they examine will ask, well what is matter? What does it mean to matter? Ultimately, this conversation distills into whatever matters to you. This is partly why exceptional writers are held in such high regard. Truly exceptional writers whose work transcends the immediate cultural milieu, regardless of whether it is accepted in their time or not. What is often recognized as the staying power of art. It's the class of writer all writers strive for, though few will risk the embarrassment of saying so.
All the way. You write for yourself. You write for your job. You write copy, prose, poetry; you write avant-garde fiction. Does it matter? Does it matter to you? Someone once asked, why would you need to get published, why not keep the writing for yourself and that's enough? This is a good question to ask oneself. It begs another. Why write anything down that you don't intend to show to anyone else. If that's the case, wouldn't it make sense to keep the words in your mind where they might never dull in their vivacity.
And we that have shed none must
gather there
And clamour in drunken frenzy for
the moon
from 'Blood And The Moon' by W.B. Yeats
Some of this is practical. Anything you keep in your mind risks the fate of being forgotten, and there are those thoughts and ideas which are so compelling that they must be made solid, in some manner, so that their concrete self might last. Even this, however, risks the rigors of time. Here we the genesis power of art, its ability to grow; where we see the natures of a child. A writer writes. The book exists, its contents are there. In that sense, the compulsion to write is as confounding of thought as one's need for reproduction. The child exists. They have been born and now their parent can think of nothing else than they want them to continue existing. Moreso, they wish for them to thrive.
As he this tale did tell,
And played on his instrument, the bloodlesse ghostes shed teares:
from "Metamorphoses" by Ovid
translated by Arthur Golding
So, there is one answer. What does it matter, the writer doesn't know. That is the nature of compulsion. It defies self-awareness. Everywhere, life is full of heroism. To act is, just what people do, and when they act it satisfies them. How many have heard the explanation: It just feels good or, It just feels right. What more is there to say about this? Perhaps some that can only reveal itself later, with age. And if from their satisfaction a truly noble child can be born, then is that anything to scoff at, as if that generation were any less valuable than another?
There is another line to consider. To write something that matters as an act of resistance against the threat of existence, something close to reproduction. Aside from glory, aside from hubris. One writes to save themselves. How many have been reading and thought something along that line. Holy shit, this is going to save someone. And the line continues, if only just one.
Her whom I'd love I'd leave before she knew that I was with her.
from "Cane" by Jean Toomer
This thinking can go many ways. There may be some absolutes, but even to the ends of those, we admit, we cannot fully perceive. If you write it, it will matter. Degree is a point of speculation that itself may not matter. If you don't write it, it may still matter. It will matter to you, the essence of it being present in your mind. Yes, there is the risk of forgetfulness, but so is there in physical representation the risk of physical loss and physical decay.
One caveat that forces the hand, is the necessity for performative action, instigated by dismissal or rejection; i.e. the necessary fuck you, that's why. It is sometimes necessary to write to prove a point. Anyone who has written in response to being slighted will recognize this. Not because what the dismissing person said was true or untrue, but because when a writer is in all their strength and power, it may be necessary to commit the tiniest act.
Writing for them will be like swatting at a fly that is already half-dead on the table. It is possible that this type of writing is what matters most, as it is, in some sense, a display of one's freedom. To not allow the compartmentalization of one’s self, being shoved to the back of the shelf. It defies failure, for the initial demand is not that you couldn't, but that you won't. So do, and do well. Give them no choice but to reckon with you.