I've heard more people are hurt each year by angle grinders than any other tool.
I've only been hurt by two power tools: one was a drill, it slipped off the screw and made the pad of my finger into hamburger.
The other was my table saw, twice. Both kickback events that threw wood at my abdomen. I'm a pretty careful user, definitely not a cowboy. Mistakes are easy to make. I'm very careful with my fingers, at least!
Angle grinders are used a lot on jobsites by jabronis who like to remove the guard and suchlike.
In the workshop I'd be most careful around the bandsaw to be honest. It's slow moving and doesn't make much noise, but will cut through three fingers before you notice the pain. At least table saws and friends have a tendency to bounce off of bone so you don't tend to end up with full on amputations.
Kickback is somewhat nonintuitive though, so watch for that!
And homeowners putting sawblades on them. Eek!
https://www.thesun.co.uk/news/3022661/husband-killed-when-he...
How does a handheld danger that can move around or be dropped compare to a heavy, stationary danger that's in a predictable location?
How does one big danger rank against several smaller dangers? What about a clearly obvious danger vs a less obvious one?
Which safety procedures can you assume to be followed? Welders wear a mask and gloves at all times, but not everyone using a table saw uses a pushing stick.
How much experience and skill should you expect the users have? Users who are expecting a tool to buck or bind will be ready for it - does it matter that inexperienced users might not be ready?
If two tools are equally dangerous in a spacious workshop, but one can also be used up ladders and upside-down in crawlspaces, is it more dangerous because of that?
Do you just rank classic tools like hammers and drills, or do you have a broader definition? Is a ladder a tool, for purposes of the ranking? Is a car?
Ah yes, simply don't make any mistakes ever ;-P
Fair enough though. I suppose the thing that makes table saws / routers / etc seem safer -- to me at least -- is because they look and sound scary. An untrained novice is much more likely to be careless around a band saw than around a table saw.
None of them sound like the router though. It's a banshee from a nightmare. I don't even like using it when it's mounted.
The router, even when you do all the above, it can jump, it can throw material off, it keeps spinning for a surprisingly long time after you power it off. All these characteristics make it less predictable. You need to understand it at a somewhat deeper level, how much can you cut, what direction to go, what direction is the grain going. You need to hold/brace it understanding that it can be unexpected and has a lot more power than you think. That's what makes it a more dangerous tool. Ofcourse properly used - it's fine.