All the examples I have come across in modern design in the living space have had one key goal; to maximize space. In a world where space is hard to create without building outwards it would make sense for designer to look and build inwards on a design. Seating is one of the most commonly experimented with today as all that is required for the body is a flat, soft surface with some kind of support in the back. These all have covered the basic necessities for a chair with the slight exception of the first example which I would say is more focused on form rather than function because of the choice the designer made to use wood instead of a more comfortable material.
The reason by them all of them having a rounded appearance is because it gives the illusion of having more space and the room being more open. Each of these designs have achieved their goal of creating something aesthetically pleasing whilst also being useful to the owner.
