It is clear that you learned to dive or taught your children to dive in the relative balmy mediterranean waters, hence minimal exposure protection. Try to do that in North Sea or our local Schelde estuary. I learned to dive as well without a bcd (people were using fenzy's as bcd's at that time), but if you are using a 7mm or double 7mm wetsuit I can assure you even as a child you need lead to go under and some way to get up again ;-)
I am a father who takes care of my sons. I did not bring them underwater in the sea, at 5 years old, in less than favourable conditions: cristal clear water, no waves, no current, reasonable water temperature (>20°C), proper equipment, and two instructors (me and my wife, and she is certified for teaching to children above 3 years).
I am not crazy...
No way that my sons could be exposed to a risky environment.
I think that people should learn diving very progressively, starting "easy", in favourable environment and employing very minimal equipment.
And evolve slowly to more challenging environments and adding progressively more complex equipment and technologies.
Unfortunately the fast OW "one weekend" course, originally conceived for tropical resorts, has been applied out of context. So very inexperienced divers are training in cold water, with bad visibility and carrying heavy and complex equipment.
Of course they have problems controlling breathing, buoyancy, trim and kicking...
But the solution, for me, is not employing even more complex equipment, as the invention discussed here.
My idea is to start again from basics: first free body, then you add fins and mask, then you add the snorkel, and teach snorkeling. then you teach free diving, and only when the student can free dive, say, to 10 or 15 meters deep, you start training with a scuba tank. Still without suit and without BCD...
And finally you add also them...
It means many months, not a weekend of training.
For people living in cold weather, it could take years, not months, and a lot of this training will be done in a pool.