Google's John Mueller was asked if it would help with web rankings in Google to embed reviews from sites like Facebook, Bing, Google, etc., on your website. John said no, not for web search, and he also warned us about not using structured data on those third-party site reviews. In short, using reviews collected by third-party websites should not help you rank better in Google Search.
Dacey Hill asked, "Is there any benefit for any local business website if their GMB/Bing/Facebook reviews are embedded or shown through API on the web pages instead of the static reviews without validation?"
John replied, "Not really, at least not for search. Also, if you do that for other reasons, make sure not to use structured data markup on reviews not collected on your site."
Not really, at least not for search. Also, if you do that for other reasons, make sure not to use structured data markup on reviews not collected on your site.
— johnmu is not a chatbot yet 🐀 (@JohnMu) February 20, 2023
John said something like this before, that local reviews are not a web ranking factor.
And the warning about using structured data on reviews not collected on your site, but collected on third-party sites, is a rule change from 2019 that so many people forget.
Forum discussion at Twitter.