My volt is already at 135k snd still going strong (knock on wood). I;ve had 2 cars get to nearly 200k miles and the only reason they didn’t was because I had better cars, so they sat for years before I got rid of them. The 100k mark might have been true in the 80s-90s, but with the precision they can build engines today, I think the new number should be 150-200k miles. So it’s more wear and tear in the interior rather than engine wear as well as safety and tech that would cause me to trade in.
I would tend to argue that 150-200 might even be low....
I have a 2006 Honda Odyssey with 212k and the only "major" thing it needs is another timing belt change. Other than that it is purring along perfectly fine. I wouldn't have any second thoughts about driving it across country (after the timing belt is changed). The van has 2 other "minor" things which are moot. The motors for the auto sliding doors are 15 years old and are wearing out. But they still work fine, they're just a little finicky sometimes. The doors can always be manually opened/closed though. And the hot/cold blend door actuator for the a/c needs to be changed ($50 and 45 minutes of time maybe). But yea, other than those things, vehicle is perfect.
Likewise, I had a 2006 Toyota Prius with 209k. The only thing it needed when I sold it was a new application of clearcoat, and maybe paint. Other than that, it was also in excellent shape. Only reason I sold it was I bought a newer MY plugin Prius...which had 141k when I bought it.
I think the 80k-100k mile mark is just about when a vehicle is properly broken in

If you take proper care of them they'll go for a very, very long time.