Given the fact that there are infinite realities, this means that our Rick is essentially immortal.
There are infinite realities, but not necessarily infinite realities in which the Phoenix protocol was both developed and never axed.
When Rick and Morty jumped after Love Potion #9, Rick specifically stated that there were limited dimensions to which they ...
According to rickandmorty.fandom
In Edge of Tomorty: Rick Die Rickpeat, the purpose of Operation Phoenix was revealed. When Rick dies in any dimension, his mind is automatically uploaded into a clone body.
Due to differences in realities / dimensions, it's possible that the Phoenix Protocol is deactivated for good in some of them.
Since the ...