For me, if I used it, I'd feel like I was using AI, even if just dipping my toe in. And I don't need it. But for all I know, it's database program and very minimal. Even if you could say its AI, it's the most minimal of minimal edge cases.
Features like spell check and grammar flaggers have been built into WP software long before AI existed and aren't even AI. There's some strange false equivelancy argument going on with this.
I suspect Grammarly uses AI now in the way lots of things do, slap an AI label on it to make it cool...