Everyone's experience will be different depending on what parts of Chicago they spend most of their time in. Personally, I rarely feel unsafe, but I also avoid the bad neighborhoods like the plague. When I'm out and about elsewhere throughout the city, I've mostly been fine. Sometimes you gotta keep your eye on sketchy looking people, but that would be the case anywhere.
But, hearing stories from friends and family, I would say that I have heard more concerning stories over the last couple of years. My mom lives in the Norwood Park area, which is historically safe neighborhood. Over the last few years, you definitely see a lot more gang graffiti scattered around the neighborhood, more reports of theft, and a lot more seedy looking people later at night than I remember when I was younger. There's also been an increase in stories I have heard about regarding shootings in the area.
Shortly before the pandemic a few friends and I did experience a very sketchy situation. We went to a Subway really late a night because a couple of my friends were hungry. This was again around the Norwood Park area. While we were inside sitting and talking, these two sketchy ass dudes walk in. They're both yelling, and one of them starts clapping at the Subway employee behind the counter and he quickly started making a sandwich. the other one kicked open the door to the woman's bathroom, went inside and you just hear him yelling random things. He comes out shortly after, grabs a bag of ships off the rack and starts yelling at the employee to hurry up. Needless to say, my friends and I got the fuck out of there.
I also have a few friends with the CPD, and they've all mentioned that crime has gotten worse over the last couple of years. I hired a former cop, who quit the force shortly after the George Floyd incident because he and his partner were shot at while on patrol in their car. He's a single dad with 2 young daughters and decided it wasn't worth it anymore. Of course, he still keeps in contact with a lot of his friends with the CPD, and he regularly shares stories of how bad things are. It's to the point where a lot of the cops, primarily in the bad areas, aren't even enforcing the law because they just don't think it's worth it. So the crime is going up and the people who are supposed to stop it don't want to.
All-in-all, if you're not in a gang, exercise good judgement, and avoid the bad neighborhoods, you should be fine.