Google has not imposed any penalties for duplicate content, but it is still an issue that affects thousands of websites regularly. Maybe someone has been using your original work without your knowledge.
Hence, if you are fighting a long and difficult battle against duplicate content SEO, keep going. Despite the taxing nature, the rewards will be well worth it. In most cases, non-original content issues can be easily fixed if you understand what they are.
I hope this guide will give you a deeper understanding of duplicate content and the issues around it, so you can improve your rankings and stop scrapers and copycats from messing with your site. (https://www.rankwatch.com/blog/duplicate-content-affect-seo/)