Google's John Mueller said on Twitter, "when it comes to web pages in Google Search, hashtags are just words, they have no special meaning or effect." So if you are big into #hashtagging everything, Google will consume it as just content on the page.
Here are those tweets:
I'm not sure where you mean; when it comes to web pages in Google Search, hashtags are just words, they have no special meaning or effect.
— johnmu is not a chatbot yet 🐀 (@JohnMu) February 20, 2023
Previously, Google's John Mueller said it was okay to use hashtags in meta descriptions. As I wrote then, I don't think it matters if you use hashtags in meta descriptions or not. I mean, it might be more eye-catching if Google uses your meta description for the search result snippet - but maybe Google is less likely to use it because it has a hashtag. I don't know. It is something one can test out over time...
The confusion with hashtags and Google probably comes when it comes to using them in URLs or links. Google tends to ignore any part of what comes after the hashtag in the URL. Those hashtags or pound signs are generally used to anchor someone down to a specific part of a page. So Google sees a domain.com/pageA.html#word as the same as domain.com/pageA.html.
It is about using them in the URL, which we covered before.
Forum discussion at Twitter.