You might've missed this earlier comment by @unregistereddev: "Compared to stamped metal, a cast metal part is brittle under impact and is far more likely to crack rather than deforming."

In Tesla's case specifically, this isn't just hypothetical: https://www.thedrive.com/news/tesla-model-y-owner-finds-scar...

The crumple zones in modern cars hide a lot of serious damage in a minor appearing accident. My sister in law was hit a few months ago and I was able to drive the car home with what just appeared to be a missing tail light and had to tie down the trunk.

When the auto shop looked at it they could see serious warping and bends at welds all over places in the unibody that would cost more to repair than the car is worth.