Lmao as a kiwi living in UK it's definitely a bad thing. Can't go on a night out in London without half dozen dudes trying to sell you coke. Same dudes who are waiting in alleys waiting to mug people when they get the chance.

If you ever see >1 person just standing around and not walking somewhere in London early in the morning just stay the fuck away from them. And if they start heading your way, run.

I know how annoying this can be, especially in some countries this behaviour is often directly associated with criminality. Here in Switzerland dealers are often (not always) just that, they make enough to not bother with anything else. They don't look like "dirty" junkies, they don't bother stealing from tourists, they basically don't look for any extra attention when the business is rolling anyway.

You've only told us that you're scared of being mugged by dealers! That doesn't even count as anecdotal evidence that it's likely.