One: mistakes. For digital, its as simple as control z, but traditional, its not that easy, especially with line work.
Two: with digital, you can easily layer images to give a picture texture, or make copies of something and place multiple exact copies all over the image. With traditional, you have to make the illusion of texture by hand, with out messing up, and you have to try your best to make copies of the object you want elsewhere in the drawing.
Three: more of a financial issue, but, over all, traditional would most likely cost you more in the long run. Sure, tablets are expensive, but you can buy one and use it for a long time. With traditional, you have to buy paper, pencils, pens, and markers more frequently, and if you get some of the nice stuff, it adds up really fast.
Four: You have to work with medias that can be difficult to work with, and also have a limited amount of things, such as color, to work with as well. Digitally, you can make any color you want and need, and make the strokes look like what you want with a simple click.
Overall, it takes more skills and creative problem solving to do traditional art than digital art. Digital art seems more simple in just how easy it is to do somethings.
It's kind of difficult to answer due to the wording of the question and someone's beliefs on what talent is. I believe talent to be a natural advance in something (in this case, in art they may grasp anatomy or colour theory immediately or soon after hearing of it, or they have pleasing-to-the-eye artwork though not having much prior practice). The results are nearly the same for digital and traditional beginning artists. The difference being how well they can erase traditionally and if their digital program has layers (and if they know how to use layers). Now with skill, after many months or years of practice, I personally find traditional to be much harder. Everything must be done with what you have access to, you can't colour pick, and figuring out blending and shading and such is much harder without a program that does it for you. As Whimsy-Witch said, it is much harder to fix a mistake traditionally than it is to fix digitally. So it takes more traditional skill to know how to fix the mistakes or how to avoid them. But for some, digital takes more skill. There's a lot of options and so many things can be done, and the lack of limits can be overwhelming and the end result may not be what was wanted. There's also having to get used to not looking at your hand (unless you have those graphic tablets that have a screen), which can cause shakiness or "wrong" results.