Yes, in the financial context they have a low risk profession. They can have greater than 90% confidence that if they do the same thing they did the previous year (likely, working very hard at a task they are very skilled in), that they will earn about the same amount they earned that year, usually adjusted up for inflation. Do you disagree, or are you using some other definition of risk?
If you don't know much about a given job it looks low risk. But a successful doctor, etc. have taken many risky decisions, with not enough information.
Bearing in mind that we are talking strictly in the financial sense — and not, for example, about risky medical decisions — can you explain what you're talking about further? What major risky investments do doctors make on a regular basis?
1. "But to break the 99th percentile - I think that was $342K/year for 99.5th percentile of single filers - you need to take on some risk. Like ... taking on high-visibility, high-impact projects that may fail - often at the cost of your regular duties - within your day job."
This is the OP.
2. Taking a bad important medical decision will have bad financial consequences - lower reputation, not so good references, patient complains leading to big losses of time - lower income in the future. Also there's stuff like which team do you join, what new technical skills do you get, which part of the world you work in. You take a lot of risk, you can expect higher rewards on success.
