You already have software that checks your spelling and grammar.
So, why on Earth would you give money to someone like me to proofread your spelling and grammar?!
The English language is vast, complex, and ever-changing. It’s far too complicated for computers to comprehend and navigate, so we can’t rely entirely on their advice. Only a human can truly understand something that another human wrote. And only a human with training and experience can review, revise, and polish that writing to make it truly shine!