Why Have Single-Pilot Operations Become Such A Hot Topic In Aviation Safety?

Some private jets that are operated under Part 91 or Part 135 regulations set by the Federal Aviation Administration(FAA) can be flown by a single pilot. Commercial flights that are operated under Part 121, on the other hand, require two pilots. Having two pilots, in addition to ensuring safety in case a pilot gets incapacitated, reduces the workload of a pilot.