I think one of the main reason why people breaking up is luck of communication.if patners do not communicate well enough or not being open to one another of what they like and dislike or what they expect out of their partners thats where problems begins and if not solved in time it ending up in breaking up.
i think the main reasons for people breaking up is unfaithfulness between partners,secondly luck of care.if partners are unfaithfully to each other or if one of them is a traitor they might end up into separation also if partners don,t care each other or they don,t support each other in any circumstance, no communication between two of them they ending up in breaking up also if there is no FUTURE between two of them here i mean some people starts relationship without look at the future eg what is the aim of their relationship?why are they in relationship?are they in relationship for granted?if this can not be taken from the begging without daught the relationship might end into hell.
people dont just break up cz they want but at times circumstances forces them to. like if ur partner cheats on u, most relationships end up to breaking.