The Vampire Diaries universe establishes a lot of lore about supernatural creatures and the states between life and death, but the concept of a concrete afterlife is certainly in need of more explanation. As nearly every character in The Vampire Diaries died at some point, death became more of a fluid state than something with finality (particularly when Bonnie and her friends managed to destroy several pre-existing afterlives). This only became more confusing with The Originals and Legacies, where even more death planes were established and destroyed, with the only constant being that dead characters could always come back if they were needed for the story.

https://screenrant.com/vampire-diaries-universe-afterlives-peace-other-side/