I don’t see this stuff on YouTube, I see it in the real world in the course of my everyday life.

Why have I only started seeing these outliers in the last few years? Also, the worst part of the videos isn't that they happen, but that they are allowed to happen. If the criminals weren't calmly going about their business without even wearing a mask and instead running from the security guard it wouldn't be so frustrating. If the news stories had a mugshot of the police arresting them quickly since their face is all over the internet it wouldn't be so infuriating. If the police didn't allow the criminals to run open air fencing operations right outside BART stations, I wouldn't be this mad.

Could there be other reasons why these videos are being uploaded more, and why you are being served them more over the last few years? Access to videography has been growing constantly since smartphones were introduced. There are now multiple platforms for uploading these videos, and doing so is easier than ever. These platforms algorithmically optimize for engagement and do this by promoting ragebait and controversy. And there are now entire, active communities dedicated to sharing/spreading/promoting these (r/PublicFreakout has almost 5M members). What you happen to be seeing may not reflect any sort of trend, either up or down.