of course it's a lot of economics. power celebs get together to make power couples to increase their income, gain more notoriety, enhance their careers etc. eventually they realize how ridiculous marriage is for them: their schedules, traveling, possibilities with infidelities etc, they move one.
bands break up to again increase their notoriety, increase their sales. they reunite several times to give that tour and increase the price that concert goers somehow want to pay, long after the band has reached their peak live. they stay apart until it's lucrative enough to re form. would you be surprised if the whole deal is planned?
what the state should do is legalize betting on every detail of these breaks like Vegas does for the Super Bowl. you can bet about anything relating to the break ups and band reunites.
from when, where the next tour will open, will they make a lame inconsequential album, how long will they stay together before the "next break up".
for celebs: will they "marry" again (usually to other people). did the couple cheat on each other (Hopefully with other celebs), ,who will be their next hook ups, (again hopefully other celebs).
now if we're talking fictional bullshit, again related to death: there's the death of a comic book character. see how long that one lasts (Superman, Captain America, Electra, Green Arrow etc.) again again notoriety, sales, and you know they're not really going to kill off a character that sells.