I think the implicit assumption you may be missing is that "know what you are doing sufficiently" includes knowing when not to do something because it involves unpredictable risks.
Like free solo rock climbing: it's actually fairly safe if you do it on a route you know inside out, that is well within your ability, and in good condition. But if it's not in good condition and holds might come loose, nobody in their right mind - and the knowledge to recognize the condition - would free solo it.
Like free solo rock climbing: it's actually fairly safe if you do it on a route you know inside out, that is well within your ability, and in good condition. But if it's not in good condition and holds might come loose, nobody in their right mind - and the knowledge to recognize the condition - would free solo it.