I do not think to buy drugs with bitcoin, the risk is too big, we better buy in a store that is common because more secure security

He was probably referring to the banned drugs (narcotics), which are normally not available from the stores and pharmacies. And the main risk associated with purchasing illegal drugs from the deep web is that you need to provide your delivery address to the vendor. This puts you in risk from multiple sources. There is a chance that the vendor can blackmail you. Also, it is possible for the cops to trace you, using the address information.
Bruh, why would they even use a legit courier to deliver your drugs? Of course right away they would get arrested since they inspect the items before they put it in a box. The courier would be a different person. Most of the time, drug deals are done in meetup. Of course they can deliver it to you by meeting up where you want. That way, you can meetup to some other town so you can pretend that you live somewhere else. You can be traced with any drug deal. In every drug deal, the other end can always end up as a snitch or it can be a sting operation. That's why you only deal with trusted people or your friend's dealer.