Why did the Prophet (peace be upon him) describe Abu Dharr al-Ghifari as someone who lives, dies, and will be resurrected alone?

The reason for the aforementioned Hadith is that Abu Dharr al-Ghifari (may Allah be pleased with him) fell behind the caravan during the Battle of Tabuk because his camel was weak. So he carried his belongings on his back and walked to catch up with them. The Prophet (peace be upon him) then said, "May Allah have mercy on Abu Dharr; he walks alone, dies alone, and will be resurrected alone." And the prophecy was fulfilled when he died alone in Al-Rabadha, and Ibn Mas'ud buried him.