If you are feeling like
there's no point in writing
there are too many books out there already
who will care about your book
remember:
your book is a cookie

There are so many different kinds of cookies.
You do not like all of them.
But that does not make them any less cookies or any less liked by others.

If you find a cookie you like, you eat it, and it is gone.
So you look for more.
If you read a book you like, you read it (and maybe re-read it). And then you look for more like it.

Occasionally, you will want a cookie that doesn't exist yet. Or one that's like a cookie you had that now haunts your dreams. Or maybe you just want to try your hand at a classic chocolate chip.
Is anyone out there gonna say, "no! no more cookies!"

Absolutely not.
Books are cookies. There are not too many books out in the world. Just because there's already one caramel chocolate chip cookie doesn't mean you can't make another.
People love cookies. People love books.

Tl;dr bake those cookies and write those books