People have no idea what "Mukti" is. Mukti is freedom from bondage of Samsara. Bondage happens in ignorance. Opposite of ignorance is knowledge. Knowledge alone gives you Freedom or Mukti. Also, remembering god's name at your last breath is not that easy when you have lived your entire life focusing on money, family, relatives, entertainment, etc. Memory itself doesn't work properly at that dying age! Also, who knows when you will die and how? Without Self-Knowledge, there is no Mukti no matter how many times you remember god's name. Gods can assist you in the path of Mukti, but it is your own self effort that can help you cross the ocean of Samsara. You cannot deny the law of karma. Your punya karma must be higher than your paap karma to get better circumstances and better Lokas. Just by remembering god 1 time at your last breath will not increase your punya in a way that all your paap karmas gets destroyed. Even Atmas who get swarga Lokas have to come back to Earth after their punya karmas gets exhausted.