The Prophet ﷺ, as is clearly stated in the Qur'aan, is dead,
(إِنَّكَ مَيِّتٌۭ وَإِنَّهُم مَّيِّتُونَ)
“Indeed you will die, and they will die too!” (AZ-Zumar 30)
There is no disagreement among all the Muslims and the scholars that the Prophet ﷺ has died, and his soul left his body. This is unanimous and the texts prove as much and no two people disagree about this. We also affirm as mentioned in the Qur'aan and prophetic Sunnah that the martyrs are alive, and the meaning of this life is in accordance to the life between death and the Hereafter, and Allaah knows best the reality of that life. They indeed died and parted from this world, and they are in their graves and alive in a way befitting that life. That being the case, then the life of the Prophet ﷺ after his death is better than theirs without doubt. If this is what is intended by being alive, then Allaah knows best its reality, and the texts affirm it for the martyrs, therefore the Messenger of Allaah ﷺ is better than them, and he will remain dead as affirmed by Allaah in His book, then in this regard there is no disagreement.