Together with Tencent's WeChat and other me-too sites they created the "self-media" cottage industry, basically lend credibility and let laymen publish all sorts of lowbrow and sensationalistic content to earn ad money.
If you check https://www.bilibili.com/, a very popular Chinese video site (I'd say also a stomping ground for anime pedophiles which the site was built upon. US listed btw.), you can find pirated US tv shows and basicially every popular yutube video, reprocessed, edited and watermarked as their "original" content, raking in money for their uploaders. Toutiao again is just the same model.
Part of the reason why Bytedance is so valuable, is Chinese just love these things, their de facto "news" source, the vast majority of people didn't receive higher edcation and doesn't want to read serious articles (which Chinese state-controlled media also lack).
Nobody care if it's original, they just want entertaining, explosive and easy-to-consume content.