Once again, I'm completely surprised how behind is western dark market world compared to Russia in that regard. Tor-based marketplaces with dead drops in parks and around the city have been around since 2013 and are now the only practical way to buy any drugs. Telegram channels have been widely used since at least 2015. Any city park has police squads patrolling the exits at night - they search people, open up your phone and look up Telegram and Tor apps if they suspect you've gone there to get a drop. Drops (they're actually called "buried treasure", or "klad" here) moved from parks to the city - you get instructions, for example, to go to some floor of a random apartment building, stop the elevator and search for a magnet-attached package behind it's doors.

I don't think that this article doesn't do a good job on the risk model because it doesn't understand how law enforcement operates - at least in Russia, the picture is completely different. Law enforcement has KPIs to catch some amount of drug dealers and users, and they have developed ways to do this reliably. So, instead of intercepting communication between the drug sellers and drug buyers, they prefer to work together with sellers (taking considerate money for 'protection') and arrest some proportion of buyers when they go for the drop.