Yea, Accessibility features are kind of OS super-powers and you really, REALLY need to thoroughly vet apps that you grant those powers to. These apps need to be actually using Accessibility to provide assistive technology for users with disabilities. I'm usually uneasy about Apple anointing itself the gatekeeper for this, but someone has to do it.

Lots of shady and well-known developers (like Dropbox) are notorious for trying to weasel their way into getting Accessibility permissions, so they can do god knows what with them to your system.