Even if it may seem like a dire situation, the final outcome is not necessarily very unfortunate. Just like the family that saw Sena as their only heir, unable to advance their cultivation, some might think this family needed to begin declining.
But now, it seems that everything is not so difficult because all things are undergoing drastic changes. I feel families always have their most powerful heirs for a reason—they have the best methods of educating heirs, and such methods perhaps should be passed down.
That is what everyone says—perhaps seemingly imperfect things may ultimately be what everyone hoped to see or even be perfect. But if things start perfectly it doesn't mean the miraculous result will be good, which is why it is said that everything is constantly changing. Perhaps the things you thought could not be changed will change under certain circumstances.