Incremental change tends to be less noticeable if you see it every day, but as someone who visits Toronto just a handful of times per year it blows me away how much the city has changed in even just the last 10 years. Once old and run down neighbourhoods that I wouldn't ever want to live in are now highly desirable places to be. While I'm a bit too young to have much perspective on the situation 20-30 years ago, from what I've learned from those who lived in those neighbourhoods back then, it was even sadder and even scary to live there.
I am surprised they were only 1/4 of what they are now.
There's never really been "scary" places to live in Toronto apart from a few neighbourhoods and housing projects. The places that people describe as scary just have a lot more "character" than other parts. You'll see mentally ill people on the street, those with physical disabilities, those who are dirt poor. In other parts of the city they're swept away or ignored.
What you're describing is gentrification. Gentrification has happened.
Of course those are just anecdotes, but the data confirms it. Crime rates have declined meaningfully over the years. Gentrification made these nice places to live, but the decline in crime is why they are less scary. Unless you are trying to imply that crime isn't scary?
I've known people that have lived in Parkdale for thirty years, and while it's better now, less petty crime, it's never been an especially violent place. "Sketchy" in Toronto means places where you can't leave your bike unattended for six seconds or where your garage will be ransacked by people every couple of years if the door isn't locked properly.
Gentrification pushed the troublemakers further away, jacked up rents, and changed the demographics substantially. It's a whole different town in some places.
I recall my distant relative and another few of my friends got a house here in Toronto when they were 1/4 - 1/3 of what they are now. All while their salary being maybe 10% less.
And then the older generation starts lecturing us... Completely disconnected with the current reality.