Yes, anchor text is ranking factor or signal, according to the official statements from Google and Google spokesperson(s) quoted below. Depending on how it’s implemented, it can be either a positive (i.e. if it provides context to search engine bots, by including relevant keywords), or negative (i.e. if the anchor text is meaningless, i.e. “click here”.
Q: “Does changing the text of older internal links to help users understand them have any downside? Can it hurt the rankings?”
A: “No. That sounds perfect. If you’re updating anchor text internally to make it more easily understandable by users then usually that also helps search engines to better understand the context of those pages” – source
Yes, but anchor text (and image alt text) helps us quite a bit in understanding context, so I wouldn't leave it out if you can avoid it.
— 🍌 John 🍌 (@JohnMu) May 15, 2017
“the better your anchor text is, the easier it is for users to navigate and for Google to understand what the page you’re linking to is about.” – source