Can true reality be filmed if people are conscious of the camera,?

big brother has shown with its demise that just letting the cameras roll on people, still produces acting roles that would win oscars ! reality tv was a saviour 10 yrs ago, cheap and easy telly to throw at us, every format done every occupation filmed, from undertakers to airports, and now cookery shows dominate as today's reality top draw..is it a case of to many channels with to many hours to fill, ? cooking shows have to be stopped, why have they emerged to beat off all challengers, bb was king of them all .once or twice a year, but the chefs and the cooking go on and on and on