Google has updated its URL structure best practices for Google Search help documentation to tell us again to not use URL fragments to change the content on that page. Google added this line, "Don't use fragments to change the content of a page, as Google generally doesn't support fragment URLs. If you're using JavaScript to change content, use the History API instead."
Here is a screenshot of what was added to that page:
Google said they made this change to the documentation to "make it easier to find the guideline about fragment URLs, as it was previously only mentioned in the JavaScript and mobile sites documentation."
Like I said above, this is not new, Google has been saying this for many many years. But if I have to guess what trigger this update, maybe the recent confusion with pound signs and Search Console?
Forum discussion at X.
