Your first paragraph: i agree to an extent. I disagree to the extent that
by climbing into a plane, you are assuming exactly the same risk as the
pilot.

In the case of the second paragraph, I would (and have) let my kids in
cars driven by others if (and only if) I had confidence in the driver's
ability, judgement, and experience.

Simply because someone volunteers to fly YE does not make them safe or
competent pilots. Statistically, GA is the most dangerous of all forms
of transportation. There is no (reasonable) debate on this point. Is it
safe? Depends on your risk threshold.

However, as a parent, knowing that GA is the riskiest form of transport,
combined with not knowing who the heck is flying your kid around, and how
well maintained the plane is, is an unacceptable risk in my book. Better
to fly with a pilot that you know well and trust.