I think we know the answer to that question.
As a writer, I've traveled out of my comfort zone many times. Sometimes it is topics that make me uneasy; other times it's something like self-promotion or social media that has made me anxious. Of course, this is normal. When we aren't familiar with something, we become nervous, fearing that we will make fools of ourselves or do or say something wrong. In reality, we are on a learning curve. Not only does it help with your end goals as a writer, but it also builds confidence.
One of the biggest challenges I've had as a writer early on is doing interviews. The first few times I've done them, I felt a bit dumbfound and not always sure what to say. I've had one journalist bite my head off because I wasn't giving her a 'good quote'. I didn't have media training and attempted to answer questions to the best of my ability.
Since that time, I started a YouTube channel. It wasn't something I did casually. I was terrified at first, but it turned out to be a great decision. Not only did it help me build confidence, but it also forced me to express myself better. I needed to be able to articulate what I wanted to say about my writing and books. A couple of hundred videos later, I now love recording for my channel, and readers have the opportunity to learn about me and my books.
I've also dealt with writing topics that have challenged me. Believe it or not, I've never been in a cartel, never sold drugs, never been in politics, never been an assassin, never been a vampire or a rock star, and yet, these are all topics that I've covered in my books. Not only have I done the research, but I've also paid attention to the world around me; the news, documentaries, films, webinars, books...there are many sources of information out there and many trails away from just the facts to more personal experiences. We have to put ourselves in many shoes when writing and give it fair consideration, and that sometimes is a challenge in itself.
Authors are faced with many challenges that aren't even related to writing itself. Marketing, media, government forms, and technology are just a few things that might come along your path. But aren't challenges a part of any career?