None of the things you mention, such as arm bands, swimming the shallow end is harmful to your survival, but not doing them and jumping in the ocean could be. I don't think many qualified swimmers would say to a swimming student, don't bother learning to swim in a pool first, just jump in the ocean with nobody around to save you and go for it. Or perhaps there are, it's just that there are few surviving students left to tell the story.
We then realise that we can swim anywhere, and adapt to most conditions. In trading terms this means we can trade in all conditions (by limiting liability when things dont work out), hence the argument against systems etc. A decent trader can adapt and make a call on the market most of the time, and if they are wrong they know how to reduce the damage. This then reduces the need for certainty, and develops an ongoing improvement in controlling emotional threats that we will encounter. Which over time will mean improved trading results.
Rather than having to try to formulate another system or bot when the current one starts to falter
All IMHO of course, we all do what we want in the end.