That's right, in that long time any club will surely experience a slightly under-performing performance that results in dropping point by point. Real Madrid, Barcelona and Atletico Madrid will be at the top in my opinion. But I can't predict who will be the most consistent club. The meeting between them might just be the deciding factor in who is on top. While waiting, we just enjoy the drama that will happen.
that's what is called a surprise in every season. Big teams can lose concentration resulting in a significant drop in their performance which is the reason for the opposing team to get rid of them in the top flight. And this is like what happened in barcelona in the previous two seasons because many were hit by internal problems which resulted in them failing to play well in every competition they took part in. And no wonder next season some teams will perform quite well or vice versa .