Comment by Ygg2

It removes a class of security vulnerabilities, modulo any unsound unsafe (in compiler, std/core and added dependency).

In practice you see several orders of magnitude fewer segfaults (like in Google Android CVE). You can compare Deno and Bun issue trackers for segfaults to see it in action.

As mentioned a billion times, seatbelts don't prevent death, but they do reduce the likelihood of dying in a traffic accident. Unsafe isn't a magic bullet, but it's a decent caliber round.