There’s nothing wrong as long as it is presented as a hagiography, producing a hagiography while claiming it’s a biography is wrong.
The only people who claim it is a biography don’t know that the word hagiography exists. Blame the Yeshiva system for not teaching English.
P.S. Rav Gifter was once giving a shiur (I guess on Hilchos Shabbos) and describing an item that could be part of clothing “like an epaulette”. Seeing the blank faces of the Talmidim, he closed his sefer and said that after you learn English, you can come back and learn here.