That's the point... knife crime is their new gun violence. Every problem solved will be replaced by some new problem - the politicians need their talking points.
How is this misleading at best? Do you have a source that suggests it's misleading? It would seem that your comment was the misleading one given that it didn't respond to the claim about violent crime in my comment and instead changed the subject to murder, right?
I can't find the original source I saw this in, but #2 in this link from a quick search gives a decent explanation about it. The original source I saw this in put it at about 2x and it was based on reconciling the definitions, not just a "guess" as this one does.