If it were mountain climbing etc. and not sex would novice teens be allowed to do it?

If it were anything else other than sex would people just turn a blind eye? This question is in general so you are forced to focus on the logic of the question and not the emotion of if teens having sex is good, natural, etc.

Imagine you discover your teen is concocting brew with a chemistry set that has the potential to blow a truck sized hole in the floor would you hand them a fire extinguisher and say “If you are going to mix explosives at least be safe?” If you knew a teen was going to travel up the Amazon when he/she has had no training all they know about it was from books or DVDs the person they will travel with are just as clueless but tell them be careful? You would not let a teen go to fly a jet if they believe they can and because their copilot had 4 hours in a flight simulator and instead of stopping them you just hand them a parachute because you feel you can’t ground them? If a teen wanted to sail around the world with a partner when neither has been in anything larger then a canoe would you try to stop them or just hand them a life jacket and say “In case you need one?” Teens and sex is about a smart of a mix as butting box jelly fish in your pool to add excitement. Yet no one even tried hard to stop it they just say either be careful, smart, or just use a condom. We know teens are going to do sex because there is no effective deterrent to stop them. It can and often has altered and ruined lives (sadly mostly the female half). Most teens have no clue the ramifications, not really, that is why there is an age of consent because they are too much a novice to have sex with anyone, so, why trust two novice engage in something with the potential to alter their lives forever and many times not in good ways when if it were playing with explosives, racing cars, climbing mountains, flying jets, etc they wouldn’t?