Okay, maybe "keylogger" was incorrect, but Grammarly has the potential to expose users to all types of security risks they might not realize are possible.
Here's a past example: https://bugs.chromium.org/p/project-zero/issues/detail?id=15...
I have nothing against Grammarly; it's a legitimate company and they seem to respond well to security vulnerabilities, but it still bothers me because a user doesn't think through the potential ramifications of using software that records every keystroke.