On any sector under three hours within Europe or the Gulf, private aviation wins on total door-to-door time by 60 to 90 minutes. The arithmetic: no security queues, no airport-to-aircraft walking time, no boarding sequence, no taxi delays from a congested commercial concourse.
On long-haul sectors (Europe → Asia, Europe → Americas), commercial first class on a Lufthansa, Emirates or Singapore-grade product is often the more rational choice for solo travel. Aircraft autonomy, cabin width and onboard service are at parity or better; total cost per passenger is materially lower.
The clean tipping point is group size. From four passengers up, per-seat economics on a midsize private jet approach first-class equivalents on the same route. From six up, a heavy jet becomes more economical than equivalent first-class fares for the entire group.
Beyond cost: the real argument for private aviation on short-haul is calendar control. A jet adapts to your schedule. First class adapts to airline scheduling. The difference compounds across a working month.