It depends on your perspective - you could argue that it was quite revolutionary or not very.

On the not very side, the introduction of rayon (not technically synthetic, but still considered man-made) in the 1920s and then nylon in the 1930s had little to no effect on the way that styles progressed. That is, there was no shift to take advantage of qualities that these fabrics possessed, largely because they were not high status and the designers ignored them.

On the other hand, rayon, nylon, polyester, and other materials had a huge impact on the textile manufacturing industry, as they rapidly gained on and surpassed natural fibers (in terms of amount produced). Sarah Scaturro at the Cooper-Hewitt argues that they heralded the beginnings of present-day fast fashion. They certainly made it possible for individuals to get cheaper material and therefore have more clothing. I am not sure whether they made natural fibers seem more expensive in contrast, or whether they actually drove up the prices.