I understand what youre saying, but the main character is not meant to be a blank slate that the reader is able to throw themselves onto. However, the reader is still able to name the MC and pretend they're someone they aren't. Thats why a lot of people read novels. They wish to escape reality and experience a story, whether it be from their own perspective, or the perspective of others.
If it helps, the description for the novel will be undergoing changes soon in order to better represent what it's about. It is a bit outdated and was made back when I wished to keep things hidden so as to not spoil. I only wished to give a general idea.
But the idea that the avatar could be an object for the readers own perspective and role in this world is staying. There are many self-insert characters in media who are nothing like their readers and have agency over their own decisions. It's their experiences and morals that bind them to us.