The Irrelevant Water Treading

This blog is written mostly tongue in cheek. Some points may be informative. Please provide your feedback.
If you suffer from self-irrelevancy, please seek professional advice.

Hello. My 5 year old is a much improved swimmer. However, swimming in the deep end is still a ways off.
When the water gets too deep, how does this novice handle it? Simply by floating on the back.
Why is this relevant? Because when I was little, I was taught to tread water if I was in trouble. I was to sit upright so just my head was out of water. My legs were kicking. My arms were moving back and forth.
Why do this water treading at all, when floating on the back is easier and uses less energy (and a 5 year old can do it)? Treading water is now irrelevant.
What does this teach us? That many conventional training methods for swimming and other activities can be reviewed to see if they are the best way. Don't assume conventional techniques are correct. A 5 year old could prove you wrong.

Regards,
Irrelevant