"A budget chair built for a high weight capacity, not for long-term comfort or durability."
The '400LBS Big and Tall' specification means the frame and gas lift can statically support this weight. It does not mean the foam, upholstery, and adjustment mechanisms are engineered to withstand the wear and tear of a 400lb user for multiple years.
This chair is an option for larger users who need a chair with a high static weight rating for the lowest possible price. It meets the size and weight checkboxes for a sub-$200 cost, with the understanding that it is a short-term product.
Anyone seeking true ergonomic adjustability, breathable materials, or a product that will last more than a couple of years should invest in a commercial-grade office chair. The combination of PU leather and non-adjustable lumbar support are major compromises.