I guess we'll see what happens this decade. In a few years, they will 'lose' Suarez, Messi, Busquets, Vidal, Pique, Alba, Rakitić... which is not that easy to replace. Real Madrid is prepared for the transition, Barca, meh, a little less.
They good some promising players and also Griez, Dembele and Umtiti (if they can both stay not injured for the next few years), but they really want to sell a few players (Coutinho, Dembele, Arthur,..) because they don't have enough money for a big rebuild. I hope nobody buys their players and that they have to be stuck with what they have.