Crash testing is important. Making the public aware of what happens in the crash is also important. This is the opportunity to observe many of unknown unknowns, that wouldn't manifest in non-destructive testing.

For cars, crash tests are routine, which is good. For planes, unfortunately, there are less common. Now, we need destructive testing for e.g. nuclear reactors (in the controlled and safe environment, of course). We used to do that, but stopped for political reasons.