I believe miracles are more for the benefit of the witnesses than the recipient. Death is a mere inconvenience for those in a state of grace. I have seen miracles myself, unambiguous things that absolutely could not be attributed to random chance, coincidence, or science. I am grateful to God for them (even if it helped others, not me) yet a person who spontaneously comes back to life after a cardiac event is still going to die someday. It shows God’s power and existence in fact; people who have seen things like this and still are not convinced, no proof will ever be sufficient. At judgment they won’t be able to tell God “but wait, you never even gave me a sign, this isn’t fair!” And no doubt there areamy people who are converted by miracles (Saint Paul, Emperor Constantine, the Germans of Saint Boniface, etc).
Heaven permanently fixes all of these problems that miracles do temporarily anyway, I don’t think anyone in Heaven really cares that they didn’t get a miraculous intervention to keep themselves alive for a few more years.