I agree with King on that. A thesaurus is great for finding words you know but don’t use often. Learning new words from it… you’re usually missing important nuance.
King is right about that. If you want to become a better writer, you need to read more good books with high quality prose and stop reading garbage. The thesaurus, while sometimes useful, can become a crutch. Stylistically the great writers will rub off on you if you read them carefully.