Not banned, but voluntarily withdrawn from the market by 3M after it was found that the chemical technology they used was leaching into the environment.
DuPont who make Teflon use different technology, that is said to not have the same risks. DuPont have issued statements assuring the market that their technology has none of the issues of the 3M products. Whether this is true or not is a matter of conjecture.
Leather care products you can trust are Leather Master or Pelle. Not sure about others, but the better products are usually sold at stores specialising in Leather furniture. They usually will have a product to clean, and another product to nourish and condition the leather. For best results, a leather care specialist can do it for you.
Yes, quality vinyl will normally perform as good or better than leather at a fraction of the cost. Nevertheless, it performs best if cleaned in pretty much the same way as leather.
Remember: Body oils and perspiration damage all textiles in time. Simply wiping over with a damp cloth will not necessarily remove these contaminants. (Water alone does not effectively remove oils).
Ash.