The crime rates in other places is irrelevant if the city you've lived in for the last 20 years has become noticeably more dangerous.
This is not "a narrative that keeps being pushed without merit", in fact the people who dismiss such claims are often the ones who live very insulated lives.
There are areas where people do drugs openly, and overdosing, too, and no one cares. A cop walked past a lady overdosing.
You should watch videos of YouTubers going to these areas if you do not want to do it yourself.
The areas are famous for tourists where most phone snatching is rampant, 18 a day at a minimum, on one famous street alone.
FWIW, I am talking about London.