First, online trans dating site is safe and friendly for transgender people. so most of transgender women choose to find their dating partners online, it means you are more likely to meet the one you want on trans dating site.
Second, not all public dating places are safe for trans dating, so many trans women choose to meet dating partners online.
Finally, large users base. With large users base online, you can easily meet transgender women in your location. You may find that it is not easy to meet a transgender woman in real life, but it can be easier on trans dating site.