Because mesh chairs have no padding, a mesh chair must be lightweight and comfortable for use in practice. Mesh chairs conform to the human spine's curve. This encourages good posture. This happens while sitting for long periods. Most models provide an adjustable lumbar system that supports the lower back.
Chairs using mesh for seats are more sanitary than ones with fabric or leather upholstery. The cloth does not absorb dirt and stains as well now. Mesh chairs can also work better for a modern office because they have a low profile.