There's also the fact that an aircraft like that may be able to carry 7 adults in some conditions. If you're at sea level in cold dry weather[0], then you'll have a lot more performance available than if you're trying to take off from Denver airport on a hot summer day just after a load of rain. There have been (usually light) aircraft that have crashed on takeoff/landing because the pilot didn't take the hot day into account, the minimum flying speed was higher than they expected, and the engine performance was too low.

[0] https://en.wikipedia.org/wiki/Density_altitude