I've gone to the store with friends from high school in the past and this girl I knew stole a few things. We found out she took a few things when we had gotten out of the store and into the car. I told her that what she did bothered me and I did ask her to please not do it again. I did end up not hanging out with her anymore.
I see multiple people stealing every time I go food shopping. Very occasionally I see them get stopped when they set off an alarm but more recently the three shops I use rarely have a security guard on duty.
The major supermarkets in the UK took price gouging to a new level and when you take into account the inflationary increases from power companies etc, a lot of people simply couldn't afford to pay their bills.
Shoplifting has become the norm in the UK to such an extent, if caught, you are unlikely to be taken to court if the value of the goods is under £200.
Unintentionally, I've been the thief. Thought I'd scanned all my items at self-checkout, but I missed one small, not super expensive item and didn't realize it till after I got home. Used to have some friends that would do some thievery, but I tried to distance myself from it so as not to get in trouble for it and eventually ended up not really talking to those people anymore. (I didn't do any of the stealing myself, but I also wasn't comfortable with the knowledge of knowing others I was with had.)
Mostly, I just see the remnants of others' thievery. They're at least kind enough to leave us the remnants of the packaging so we can scan it out for inventory purposes. My favorite is half-open cases of variety pack foods, especially when there's the same flavor already on the shelf.