Nearly every commercial made fastener runs out vs having a relief cut, because they're almost all rolled vice cut. So you're saying almost all fasteners are stupid?
Critical fasteners will have reduced shanks that are smaller OD than the thread ID to have more predictably controlled failure, whether cut or rolled. A precise relief cut would usually equal the thread ID and would function basically in the same manner but is not as predictable. But both are designed points of failure much more so than a thread that runs out.
A failure in a standard bolt is very likely to occur somewhere in there threads, but not likely in the runout because there is more material there. Either way it's not predictable so you don't design anywhere near it and it's certainly not a designed failure point.