It is not accurate to say that most stars in the universe are dead. In fact, the majority of stars in the universe are still alive and actively going through their lifecycle. Stars are born from clouds of gas and dust, undergo fusion reactions that release energy, and eventually exhaust their nuclear fuel over millions or billions of years.
While stars do eventually die, the time it takes for a star to exhaust its nuclear fuel and reach the end of its life varies depending on its mass. Less massive stars, like our Sun, have lifetimes on the order of billions of years. More massive stars burn through their fuel more quickly and may only live for a few million years.
It's challenging to estimate the exact percentage of stars that are still alive since the universe is vast and our knowledge of it is limited. However, based on current understanding, it is reasonable to assume that the vast majority of stars in the universe are still active and shining.