> Grammarly is an application that I don't get.

You write like a native speaker, so I'm not surprised. But imagine having a few years of school-German, and then taking a German language job. I'd bet there would be times you'd want a writing assistant, too.

There are also plenty of native English speakers who for whatever reason got a crappy education, and didn't get a lot of writing feedback.

As far as corporate security goes, you are correct, and we ban it. But I get why people want it.