Oh look! It's a bunch of trick/loaded questions, what a surprise!
So here's some bullet points:
No, you're not saving the world by writing your sonata in B minor. No, it probably won't change anyone's life if you can get it performed/recorded/whatever. No, it probably will not even matter in a grand cultural scale unless you already matter in such a scale yourself. No, most of what you're doing has been done before in much the same exact way so your claim to originality is tenuous at best. No, you'll probably starve to death if you try to make a living out of composing. No, you're not better than anyone because you can put some notes together and feel smug about it. No, thinking about it in some grand scale only highlights how masturbatory an exercise creating art really is regardless of whatever superficial motives you think you have. No, regardless of how you think you can dress your gibberish as intellectual, none of it matters since that word has lost basically any significance since people started using it to describe gibberish they didn't like but had to put up with to look smart. No, you're not going to incite some great revival of some music style because you write in it, nobody could give two poo poos about the fact you can write music that sounds like the music someone much more famous and important (and most likely dead) than you wrote. No, you can dress your discussion of composition in any way you want to, but it won't convince anyone that what matters isn't just the end product on the dance floor, so to speak. No, you shouldn't stop writing music for any of the reasons mentioned above, but if you want to stop it won't be a great loss and there are millions of others that will appreciate having less competition. After all, there is only so many ears and only so much time in the world.
Depressing? Nah.
I like challenges.