There's nothing Fandom can do to "save GameFAQs". It has always been a JRPG and Nintendo site. JRPGs have been in massive decline since 2007 and Nintendo has done of things that aren't really popular with GameFAQs boomers. Walkthroughs and FAQs have wikis and youtube videos that are often superior to the old GameFAQs text format. There's not much Fandom can do to attract new users. A vast majority of users here are late 30s/early 40s.
That said there are things Fandom has done to make the site
worse
and it goes beyond the whole CE/261 drama that some people are taking way out of proportion. Intrusive ads, lackluster bounties, and outdated website design are the main takeaways.