From what I have observe... Her Childhood Friend is OP when it comes to Physical attack... Little did the MC tried testing his Magic.... If he did, they can still be together as
MC: Sage
Childhood Friend: Sword Master
but it needs to be like this so... The story would Progress.
To make it short : The person who got hurt will let his/her heart to move on quickly while the person who hurt their other half will regret it afterwards while moving on is reverse.