In my headcanon,
Palpatine DID die.
Sith are known to be able to possess objects (Darth Bane in Clone Wars)
Palpatine possessed his own corpse using the darkside and survived in the wreckage of the Death Star II. When Ochie found the Death Star II remains he discovered Palpatine. Palpatine instructed him to take his body to Exegol and the dark side worshipers (Aftermath book series) grouped up on the planet.
Palpatine’s plan all along was to get Rey to come to him so that he could possess her. He knew Ben would not kill her, so he told him to in the hopes that he would bring her to him or she would come own her own.
When Rey refused to “strike him down” Palpatine decides to drain her life force, like he did for Padme, to restore his own health.
As for the Snoke situation, until Palpatine was ready he wanted to throw off Luke to his scent. What better way to do that then to make a puppet version of yourself. It is a little wonky but definitely something Palps would do.