It's interesting that a $35K price point even makes sense for a car that could conceivably be designed to last 400K miles.
Edit: Yeah missed the k. Never heard that one brought up. Also doubt Tesla's will last much longer.
Mechanical wear, the rings don't seal as well against the cylinder walls as they used to. Valves don't sit in their seats as tightly as when new. And so on. As for other problems, I already listed a few. Think of the niggly things your last old car had. A Tesla, diesel, or any other car is not immune to those problems.