Possibly but his job is to win trophies. Recently we got a wee glimpse of dembele and with coutinho too they look tantalisingly good. He is rebuilding them and with hopefully griemannz and maybe lemar next season they will be once again the most awesome attacking force in the game and jaw droppingly good to watch.
Barcelona have been the best team in the world since about February 2005, the times they have not won the big trophies have just been due to dips in form, rebuilding and transitional phases. They are the best team on the planet at their best and have been for a long time. Valverde is doing a tremendous job of making sure that will continue for a while yet.