I am looking at new kitchens at the moment and have noticed that
they all have a recessed plinth.

If you have integrated appliances, the door is hinged not quite at the
bottom. This means that the door attached to the front will actually retract
inwards at the bottom. If the plinth is too far forward, the lip of the door
will catch on on it. As few kitchen manufacturers want to sell kitchens
incompatible with integrated appliances and they want to use standard
specification parts, the plinths are recessed.

Christian.