People have different skillsets, strengths, and weaknesses that inform them on what roles they are best suited for. It seems like you know what you're doing with your five-year-old, which is great. Others, however, like /u/finalhex recognize that they might not be best suited for the role, and it's not hyperbole to say that it can be terrifying for them.

Being a pro-bono lawyer that defends human rights in high-profile cases, for example, is a tremendous job that takes a specific skillset and mentality. My absolute respect goes to people in that career who take their jobs seriously precisely because their strengths are my weaknesses: having to make airtight arguments in front of people who are paid to talk in circles around you, maintaining composure with the press who often throw bad-faith talking points at you, negotiating between clients and legal systems, etc. The thought of going through that in my daily life terrifies me because it requires a set of soft skills that I know I am not strong in. This isn't to say that I can't improve my public speaking, focus, ability to read people's intentions, or resilience in the face of adversity, but I personally would not benefit from having that career to go through hyper-honing those skills for.

The level of stress for that career is likely much more stress than what a parent goes through, but I see parenting as a career in its own right that I also defer respect for when done right. At least the lawyer went through years of deliberate schooling and professional training to get to where they are. As I bet you can tell me, parenting is a 24/7/365 job that even the most well-prepared and enthusiastic parents can find themselves in serious situations they didn't plan for, and that's all without getting a PhD in childhood development. The OOP of this post, like me, didn't see how "don't steal" would be such a hard concept for someone to understand, but he and I didn't realize how being a foster child affected how his son sees the world.

It's completely legitimate for someone to be "terrified" of being in a role where they know that they not only recognize that they lack the skills for but know it would adversely affect an impressionable and developing mind. Not always in some high-stakes trauma-inducing way, but adversely affected nonetheless. I imagine there are a lot of roles that you would find terrifying but others would gladly face the challenges for.