Why do women cheat?

Seen a lot of posts about people saying

'my 3 years of relationship is destroyed'

'my girlfriend cheated on me'

'i cought her in act'

dont get me wrong, men cheat too but im just curious about why women cheat, i dont get it tho, 3 years of relationship getting destroyed easily, why do people cheat? if they are unsatisfied they can just break up right? why hurt the other one so bad that they cannot trust anyone their entire life? man fuck those who cheat