I think people in Skyrim are continuing writing journals for the same reason nobody in Star Trek thought about stop producing red shirts
OMG, you made me LOL. Hence, as we all know, "if it's red, it's dead."
Meanwhile, if you are trapped and death is imminent, why not leave a final word to those who might find your remains?
"Dear sir or madam,
It pains me greatly to be unable to meet you face to face, in the corporeal sense. However, I'm trapped in this cave and the water is rising... gosh I'm thirsty. Anywho, on my person you shall find a key to...."