IMO not using LLMs is a big plus in my book. Grammarly has been going downhill since they've been larding it with "AI features," it has become remarkably inconsistent. It will tell me to remove a comma one hour, and then tell me to add it back the next.
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.