This concept does not exist for me. There is an underrated one, but there are no overrated ones. And here's why:
1)An author can sell well, even if he writes bad books like Colleen Hoover. Many people read it like chewing gum for brains, although its plots are ridiculous, the characters are empty and the text is too simple.
2) Or black PR can play with him, as it was with Dan Brown when the church tried to cancel him because he created books based on conspiracy theories (The first point still fits him).
3) It may also be that the author just released the book at a good time, examples, Rowling and Sarah Maas. Their books were published when there was no competition among the genres in which they were produced. Rest assured, if "Harry Potter" and "Throne of Glass" had been released in our time, they would have been lost among the same books.
P.S. Sorry for the misspelling "doesn't". I forgot how to spell it correctly.
by mystery5009