Its like poisenous plants. Being poisenous doesn't prevent the single plant from getting eaten. But it makes it very unlikely, that a lot plants of that species get eaten. So while a single iPhone might get stolen, overall there are less if many thieves targetting iPhones. They don't bring money, but increase the risk of landing in prison.
> So while a single iPhone might get stolen, overall there are less if many thieves targetting iPhones.
Do we have data to show this?
> They don't bring money, but increase the risk of landing in prison.
I also don't think the risk of going to prison for theft in London is that high. Sure, stealing an iPhone increases it, but an increasing an insignificant risk by a factor of 10 could still leave it being insignificant.