the interior was literally falling apart because it was in the SLC area from new
Some cars also just don't weather the sun as well. My brother's Ford Fusion is the same year as my Cruze and has actually had way less sun exposure but it looks like it spent a few years on the surface of the sun. All the interior plastics have long since lost their finish and are pretty crispy. The rubbers too are pitted and have had chunks fall out. I have a picture somewhere of the steering wheel looking like the surface of the moon. Meanwhile, its exterior plastics are in great shape somehow. OEMs have gotten way better at sunproofing plastics but sometimes they'll cheap out.
I am continually shocked by how good the plastics on rusty cars are here in the PNW. I think you hit it when you said that it's how long cars stay nice, not just how long they stay functional.
They're absolutely amazing cars and engines. The Platinum is the trim to have, sure you're down 50hp but the extra luxury is worth the tradeoff. Especially if supercruise is there like this car has. I've put quite a few miles on a car that is just like the one for sale and it is such a good roadtrip machine. Even drove one in a total whiteout snowstorm and with snow mode enabled it drives like dream... you do need to knock the ice off the supercruise sensors every 50 miles or so though if it starts to build up. If I had the cash I would buy one as long as it is under warranty. I have concerns about long term parts availability.