A lot of the graphics that explain how CRISPR work show this very careful snipping of a strand of DNA. Tiny little scissors making pinpoint accuracy revisions. I think that's lead to a deep misunderstanding for most people (including myself) on how this technology actually works.

CRISPR is amazing, but it's still a fairly blunt tool. The article talks about one way: guide RNA can often bind to sequences that are very similar to the intended sequence, but not exactly, meaning it's probable that for every intended cut you're making several unintended ones. The "scissor" action itself, Cas9 protein, is less like a scissor cut and more like a jagged tear, which can damage surrounding DNA.

The repair pathways themselves are also imperfect. It's not a copy/paste like infographics show, it's more like emergency duct taping broken ends together.

All of that stuff combined...Again, amazing technology, but I get extremely nervous when I hear people talk about introducing CRISPR-based gene editing into the human gene pool. The generational effects there are still entirely unpredictable at this stage, could be disastrous, and any actual paths to trying to roll things back would be deeply ethically fraught.