Tack needs to be maintained religiously. Synthetic tack can be hosed down or washed in the washing machine. It's lighter in weight, easy to care for, and less expensive than leather. Leather, needs much more care. Inspect it every time you clean it. Wash it every time you use it, and then oil the leather parts a few times a year.
Browse some different types and styles of synthetic and leather horse tack available online.