Don't think of this as dropping your kids in say, the High Sierras or Death Valley ;-) This is actually an extremely safe thing, nothing much can go wrong. Some supporting facts: Our entire country (The Netherlands) measures roughly 161mi by 93mi and is densely populated. There's always a dwelling nearby. Consequently it's impossible to get really lost. We also have no natural dangers to speak of, no deadly animals,…
I think it is important to say this indeed. I also did "dropping" as a kid, and later with kids, but the only thing that "spoiled it" was cheaters that find a phone in 1 hour and call a cab. I haven't heard It being done for a while now, is it still a thing in this time of fear and smartphones?
TBH last time we did one each group just had one adult with them, they'd just stay silent the whole time and follow along. So it was a bit boring. But we did that because we only had a few people and one car, and couldn't keep track of the whereabouts of the groups otherwise.