It’s how they’re all done now. American style I guess. We have short attention spans...
But it's not how they're all done at all. There are different styles: some with frequent recaps, some with previews ahead, some telling one continuous story with no such devices. It depends entirely on the intended audience, the time-slot, the channel.
Planet Earth and 'Department of Complaints' or whatever this show is are both broadly under the umbrella of factual, but clearly are both different styles. Similarly, Line of Duty and Doctors are both drama. Different styles, different audiences, different budgets, different times of days, different ambitions.
If you don't like it, it's a good idea not to watch - but it doesn't mean that all of the other programmes in the genre are the same.
Steve Williams and MetalGearRex gave kudos