For instance you could have one wallet with £10m on it an another with £1.5m. You could certainly convince adversary that they got bad intel and £1.5m is what you have. It's better to lose £1.5m than £11.5m.
There are other scenarios like journalist taking compromising photos. They could have two sets of photos - one with key photo missing and another with key photo in the set. When questioned by adversary they could claim they have missed and didn't take the photo and show the set as evidence.
Someone in abusive relationship planning on leaving the partner. They could have a folder with properties they are interested in without the property they are actually going to rent. When caught they could convince the partner that they were just looking, but have not committed to anything.
If you are not in these kind of situations, sure this additional layer may not be to your interest and frankly you wouldn't have to use it! But for many people lack of such feature is a deal breaker.