Well, it really tells you haven't tried buying drugs on Telegram. It is all scammers, every single one of them (maybe with the exception for prostitutes but I bet most of these are scam too). There is pretty much 0% chance you'll buy drugs or fake documents using the geo search. They will scam you for a transfer and disappear. It really is no that different from a spam email, just different media and targeting.

That said, you CAN buy drugs on Telegram, sure, it is just not as easy as everyone seems to think. You need to know the account name of a service that delivers in your area, you need to be reeealy careful when typing the account name because for every real drug seller account there are multiple fakes with slight variation in the name that fish for people using search, and then even if you have a verified account and they sold you drugs last month, there is like 30% chance that the account have been compromised and now you are talking with scammers again.