Logging solves this problem. If OTel and observability is attempting to position itself as a better alternative to logging, it needs to solve the problems that logging already solves. I'm not going to use completely separate tools for logging and observability.

Also, "crash" here doesn't necessarily mean "segfault" or equivalent. It can also mean "hang and not finish (and thus not end the span)", or "have a network issue that breaks the ability to submit observability data" (but after an event occurred, which could have been submitted if OTel didn't wait for spans to end first). There are any number of reasons why a span might start but not finish, most of which are bugs, and OTel and tools built upon it provide zero help when debugging those.