There is no area in this country where you have to look over your shoulders every two seconds to avoid being stabbed, or even have to worry at all. You can get stabbed, but it’s either a freak incident with extremely low likelihood or you’re actively involved with dangerous behavior such as gangs or getting into fights.

It makes a ton of sense to prefer to live in South Kensington, because it’s posh and overall nicer. It does not make sense to live there because you think you might get stabbed if you wander out into the ends.

London is meaningfully more safe than, say, Caracas. South Kensington is not meaningfully safer than Streatham, because it’s already ridiculously safe for regular people going about their business.