Private jet makes a good point. But it's the lack of candour in the TV presentation that discredits many of these expeditions for me, rather than the backup itself. As I said in my post before last above, viewers shouldn't be treated as both ignorant and gullible.
If the spectacle in the documentary is to be enhanced with air-to-air and ground-to-air shots, as opposed to the simple expedient of head-mounted and airframe-mounted mini-cameras, that's fair enough. If the team on the camera aircraft, in addition to flying ahead to prepare for photography at the next destination, takes the opportunity to make other arrangements such as HOTAC, diplomatic clearances, fuel, etc., before the star arrives there - fine. As the a/c will inevitably need repairs, sooner or later, after an arrival, why not include a flying spanner in the team? In the absence of an essential part, why wait for days or weeks in the middle of nowhere if the camera a/c can fly the hundreds of miles to obtain it? If the pilot-star needs the assistance of a co-pilot/instructor on some of the legs, I can even live with that.
However, some credit for the team and its less mundane inputs - without boring the pants off the viewers - should not seriously undermine the credibility of the presenter and his/her achievement. And if it does, so be it.
Amy Johnson flew genuinely alone, and with primitive equipment, as did several of her contemporaries of both sexes. Much more recently, Ellen MacArthur accomplished something perhaps even more remarkable - even allowing for the benefits of sophisticated kit and communications - non-stop in a boat. Not sure we'll see quite their like again, but maybe Johan Wiklund and Amanda Harrison will be worthy successors.
Following in the footsteps of the great pioneers can be no less interesting as entertainment when it is done with honesty and humility. Attention should be focused on the original achievement, not the star of a synthetic re-enactment.