Alot of places, you can't have fires even with fire pits, even in established campgrounds. This has been true for decades. In the backcountry, certain cook stoves are even banned (e.g. the ones that use twigs) because of the fire danger. I have had rangers come by, checking....
A fire in the Tahoe area, even in an established campground, will send up smoke and sparks. Unnecessary danger, and all our fire fighting personnel are needed for fires we have no control over.
One spark, and you've got square miles of conflagration, hundreds of homes destroyed, billions in damage. I feel confident that if the teens built any kind of fire, the local fire department would have been there in an instant.
Look at the photos of the campsites ^^^^. One spark....
I haven't used a campfire for maybe 40 years. I'll go to one if someone has one lit and I want to get warm or would like company, but I never build one myself, even in an established campground. I do this out of "leave no trace" (a single fire mars a piece of ground permanently, and animals need the woody material for survival), but the fire risk is unacceptable almost everywhere.