we can infer from the passage that people changed from cotton to synthetics because ……..

The increased use of synthetic fibres greatly reduced the demand for cotton fabrics, and cotton's share of the total U.S. fibres market dropped from almost half in 1966 to about 30 per cent two decades later. This natural fibre offers unique qualities of comfort and wear, however, and consumer demand for all cotton fabrics, or blends of cotton and synthetics, is on the rise once again. There is a growing market for the long-staple cotton fibres that can be spun and woven into high-quality shirt fabrics. All cotton fabrics with a durable-press finish are now available, and experts expect that, in time, cotton will rival the synthetics as a convenience fabric.