Although the difference in the concept of life between Jedi and Sith have been explored before (Jedi become force ghosts and live on in spirit while Sith live on clinging to the mortal plane, the most prominent example being Darth Sion), it has not been introduced to the movie seeing audience.
the only line we get regarding prologining life is about Darth Plagueis, a Sith legend who could create life due to his knowledge that he could keep people from dying. However, he is unable to save himself which already sets a stripulation (assuming Palps isn’t lying which he could be to seduce Anakin).
it is very possible that Palpatine throughout the years built on this knowledge and thus mastered the ability to also “save himself” from death but then that should be shown on screen in RoS and hinted at throughout the trilogy (maybe Snoke is busy with research and Kylo is constantly tasked with finding holocrons but didn’t know why until RoS). It could have then explained Rey’s sudden ability to give life to others which would have tied better with maybe her also being a clone and getting Palpatine’s knowledge by osmosis since giving life is not a power learnable from a Jedi (the light side).
This also raises the question then that how are we to assume Palpatine is really dead. Reflecting lightning back isn’t much more different than shocking yourself while falling down a shaft and I doubt reflecting force lightning would actually kill Palpatine (he survived Windu). Plus, we now know that Palpatine has the knowledge to “save himself” and if he can do that after falling down a shaft, exploding, and getting caught up in the Death Star exploding, I don’t see why he can’t do it here. Hence why having the ability to revive without some limitation is bad storytelling.
