My brief unscientific observation is that every INTJ I know struggles with concepts of death and more importantly decrepitude.
Not to say that other types don't.
Seems to me that those who have a high degree of need to control their situation (which also makes them successful, goal oriented etc.) take it the hardest when the body starts to do what it must in the cycle of life.
Someone said - Nobody wants to die, even those who want to go to heaven.
Getting old does not have to suck. With time, reflection and experience, aging can be a wonderful thing. No longer we have to waste time on stuff that does not matter and can discern true friends from acquaintances. Hopefully one has more resources when older to focus on and do things that as a child we could only dream of but had neither the agency nor ability to execute on.
We could hate our bodies for not being as resilient when younger or we could love it and tend to it even as we thank it for having gotten us this far for many don't even get the chance to start their journey at the gates of life and so many others have since fallen by the wayside.
Death in the modern world is easy - there are so many medical innovations and drugs etc that were not available to thousands of generations of our ancestors, many of whom perhaps suffered horribly for what we now can so easily assuage. On top of it euthanasia is an ever increasing and acceptable option. So I submit that in today's world, it is not death and decrepitude that are so much an issue but having lived a life that one can honestly say has been well lived (we all can make clever arguments and bullshit others but not ourselves, especially in the long run).
So fear not dotage or the grim reaper but the gentle solace of complacence and inattention to living.
I met a traveler from an antique land,
Who said—“Two vast and trunkless legs of stone
Stand in the desert. . . . Near them, on the sand,
Half sunk a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things,
The hand that mocked them, and the heart that fed;
And on the pedestal, these words appear:
My name is Ozymandias, King of Kings;
Look on my Works, ye Mighty, and despair!
Nothing beside remains. Round the decay
Of that colossal Wreck, boundless and bare
The lone and level sands stretch far away.”