Google's John Mueller explained that Google doesn't really care who wrote the content on your site and saying someone else wrote it and you did not write it won't save you from ranking issues related to the quality of that third-party content.
The question was "websites which collects USG reviews have a lot of thin / low quality content. Obviously only few rank, which is fine. But will this hurt the overall website? How to prevent it? For example, use review structured data markup? Or use noindex tags for user-generated content?"
In short, if you have user-generated content on that site, does Google understand that and not count the poor user-generated content against you? The answer is, that Google will count it against you since you allow it to be published on your website.
John Muller responded "What's a USG review in that situation? In general, user-generated content or not, what you publish & make available for search is what is used by search engines. There's no "but the site owner didn't write that personally, so don't count it against them" aspect."
Here are those tweets:
What's a USG review in that situation? In general, user-generated content or not, what you publish & make available for search is what is used by search engines. There's no "but the site owner didn't write that personally, so don't count it against them" aspect.
— 🥔 johnmu (personal) updated for 2022 🥔 (@JohnMu) August 19, 2022
We've recommended that for a while now, yeah.
— 🥔 johnmu (personal) updated for 2022 🥔 (@JohnMu) August 19, 2022
This is not really new, we covered this exact concept several times...
Forum discussion at Twitter.