Came to think of a more recent example: If we want to look at a WW2 plane or ship today, in person, which are there more of: Those that got shot down/sunk and are at the bottom of the sea, or those that survived the war and were left at the mercy of growing old? Personally, I can literally speaking only think of two WW2 era ships that are still possible to see without diving gear, the USS Missouri and the HMS Belfast. There's probably a few more, but even compared to those that were sunk in relatively accessible depths, they're bound to be outnumbered.
Long story short, growing old at the mercy of the military that's operating it is more dangerous to any military vehicle than being blown to bits/sunk/shot down/crashed if it actually wants to stay around.