Well... he was the sage in past life, and most likely the one that have best knowledge about magic too.
After he decided to reincarnated, the progress of magic probably stopped since few/no one else could improve or teach most of high tier magic.
I don't think I can like the male lead, especially knowing he have actual list of "kindness".
But it's just 16 chapter, it's short enough to enjoy this even if the story is garbage.