Being dyslexic, I was an avid Grammarly user. Once it started adding "AI features" the deterioration was noticeable, I cancelled my subscription and stopped using it a year ago.

I also only ever used the web app, so copy+pasting as installing the app is for all intentness and purposes is installing a key logger.

Grammar works on rules, not sure why that needs an LLM, Grammarly certainly worked better for me when it was more dumb, using rules.