Protip: if you spent nearly two decades in full-time education but somehow remain unable to construct a proper written sentence in your native language... your parents should ask for their money back.

In principle, I agree with you. But long ago, I worked as a copy editor, and can tell you that time in school has a weak correlation with the ability to construct a proper written sentence.

But no, nothing I've seen from Grammarly suggests that it would be much help.