The issue is less the wear and tear of the battery and motors and more the wear and tear of everything else -- suspension and brake components are going to need replacing, along with radar and ultrasonic modules, etc. These parts will be at least partially end-of-life and hard to get by the end of that 20 year period. Federal law requires some amount of parts availability for 10 years + some release of part designs to the aftermarket after that, but I have a hard time getting parts for 21 year old Ford designs that were less than popular, so I would be surprised if early Tesla models are having an easy time 20 years on. This gets much much worse as you start to look at the number of abandoned EV models from the Big 3, the abandoned/dead/dying companies (Fiskar, Lucid, Lordstown, etc). That doesn't hit the vast majority of all EVs, which are just Tesla, but it does put a dent/makes the buying decision harder. Now expand that to not just Tesla, but what does Tesla do with a Cybertruck? Like all things, the specific product decision matters a lot, and this is a new area (even at 14 years old) so there will be lots of people who optimized for cost and not maintainability.