Only idiots are communicating their addresses unencrypted - PGP encryption for addresses is standard. So the only way for your address to be matched to your dark net activity is if a.) the person you are buying from gets busted and b.) the person you're buying from doesn't destroy the address after they ship the package.
The police use undercover drug dealers on the streets. Why wouldn't they use them online, where it is much cheaper and safer.
The political fallout in Canada for running a raid where nothing is found is massive. Warrant mistakes have landed police agencies on the front pages for weeks, if it came out they were doing raids based on next to no police work, not only would the police be under fire but the judges would be too.
> Only idiots are communicating their addresses unencrypted