I am going to wade in late on this.
My experience in industrial safety and kayaking lead me to believe that there are no accidents. There are a series of events and choices that lead to incidents that become notable or cause injury or loss. So, you choose every day things that may or may not contribute to your safety. They start way before you get on the water.
You choose whether or not to check your boat at the start of the season or before a big trip. You choose what equipment to carry in your repair kit. You choose whether to learn how to manage your boat with and without the use of a rudder. You choose to learn to understand wind, water, and waves and make appropriate choices. That might make the difference between inconvenience (something breaks that you can fix on a beach easily), something that causes you minor discomfort (you have to paddle for the day without the benefit of seat back support) or something that causes you to have to call in help and and cancel a long trip.
My first overnight kayak trip was 14 days from Fair Harbour to the Brooks. Lots of open water and opportunities to learn. Knowing what I know now, that probably wasn’t the smartest choice, but we were 4 people with extensive back-country hiking experience and sound decision-making skills. I remember being terrified at at least one point. And I know that we spent at least one afternoon on the beach as we waited for the evening calm to continue on down the coast.
Someone has already addressed the probability versus impact risk management matrix. It works. You mitigate the items that are high risk and high probability though specific planning and equipment. You have to be aware of the “black swans” that can cause serious injuries and fatalities and can’t be predicted. Basic safety (wear a PFD, wear a dry or wet suit in big and cold water, carry a radio, get some education) means you have the capability of dealing with most things.
Each of us have our own risk tolerance. As you point out, the more you know and the more experience you have, makes you aware of the possibilities. It also gives you the capability and skills to deal with those possibilities. So, yes, people go out and they do things without the requisite understanding and equipment and they get away with them, or not. They are lucky, or not. And people with a lot of experience and knowledge are sometimes in the wrong place at the wrong time, like the recent avalanche deaths in Alberta. And some people never leave the beach.