There are situation it makes sense. Mostly around needing a specific feature by a certain date. Maybe for a particular sale, or maybe to lure a certain investor

There are situation it makes sense. Mostly around needing a specific feature by a certain date. Maybe for a particular sale, or maybe to lure a certain investor in. Either way, if your team is saturated already, and the new feature is something they aren't fond of building (eg: something heavy on frontend when your team is mostly backend), then a contractor or consultant is often the only way to have it built on time. Finding the right employee can take time, and hiring the wrong person can destroy a team's productivity. Better to pay a premium than to get burned.