Hi Conan, I’m glad you found my article helpful. I do think Grammarly is great for catching some mistakes and help with commas. (I need lots of help with commas.) But it doesn’t know everything and you can’t just blindly follow it.
Have you tried using the Hemingway Editor? It’s free and can help identify passive voice, complex sentences, etc. Again, I think you have to make your own decisions on its suggestions, but it can be helpful. And it’s free :)
Thanks for your comments and good luck with your writing.