Define "soft jaws".
Are you talking about "non-marring", generally plastic jaws? If so, yes, I use them all the time. I've got 3 separate sets that slip on and are held by magnets. The most used is Shop fox with sort of a rubber face and aluminum body. I also have some that seem to have a steel core, magnets, and a "molded over" rubbery body that includes "V" grooves across and vertical for holding shafts or tubing. And a copper set with arms that sort of wrap around the vise jaws. And I have some aluminum jaws with "V" notches. But those are all generally for hand work.
Then there are "soft jaws" for machine work, and I use those too. In this case they are often aluminum or unhardened steel (as compared to typical vise jaws that are hardened). These are generally used to either cut a pocket to hold some add shape as needed, or sometimes so you don't risk a cutter when you accidentally or intentionally cut past a part into a jaw.
There are many kinds for many purposes.