At about 1.4 it's still pretty low compared to American cities. It's also not really "getting up there" as it appears to be on a relative decline lately.

There's probably some examples, but the US has such an outsized per-capita murder rate that it's not particularly comparable even when trying to select the best examples. If you stretch the definition of "major" and "comparable" then it's possible to find examples where they're somewhat similar but it requires a lot of stretching and is no longer representative. There's hundreds of cities in America with a murder rate higher than that of London. The US has a homicide rate approaching something like an order of magnitude higher than the UK (8/100k vs. 1/100k last I read).

London is quite low but unfortunately death by stabbing in the teens-to-20s age group has increased dramatically over the last two decades.

If you're not in that demographic, you're probably fine.

UK is not Europe. London is not a European city.