It becomes a human story, yes. He maintained a durable system rather then junk the whole thing after ten years.

Would he have been better off buying four new cars in the meantime?

There are marketability factors at play here.

I know a guy down south (i.e. no rust) who's got comparable milage across his personal "fleet" of '99 Town and Country minivans that he's been running since the 00s. Kinda hard to put a mil on any one of them when he's only one guy but whatever. I know another guy who's got >500k on a Jetta that he runs on waste motor oil from his job and removed all the seats from because utility vehicle.

Nobody will ever write a story about them because "hur hur hur, well kept Toyota" is considered admirable and bending a crashed Town and Country back into shape because you're invested in the platform and learning the ins and outs of diesel combustion the hard way so you can use "free" fuel are considered trashy.