I'd say the real danger isn't mechanical failure but a combination of mechanical failure and an insurance claim event...
When I first got my 2016 it got a love tap from a chrysler pacifica -- a small dent in the rear corner that cost roughly a honda fit to repair; insurance paid the cost but if the car were worth $13,000 they would not have paid $13,000 to repair what was a mostly cosmetic impact.
So if I paid $15k to replace the battery and $7k for a drive unit, and then I got another pacifica love tap, I'd total the car and be $10k in the hole for my troubles.
That said, if my car asks for a drive unit, I may just shrug and pay for it because I don't really see a "new" or used car that's as good as my current S, at least for the trouble of $7k. Then it asks for a new battery, and I make basically the same decision, because what car am I going to get for $15k that's as good as the S I know, even if that thing has the silly front nose cone and AP1, it also has FUSC so that's something right? Then comes the love tap from the pacifica, or let's say a nitwit in a rivian decides to cream my car, actually totalling it -- boom I've got $12k from the insurance to "replace" the car and am otherwise boned... because the car's (at least to me) worth much more than some random $12k S refuge from copart that smells like stale farts and has a timebomb battery...
Life's full of hard choices, I guess...