Google's John Mueller said that semantic HTML is not a quality signal used in Google Search for ranking purposes. An SEO said "Proper HTML semantics and tag hierarchy must be a quality signal." John Mueller responded saying "I don't see it as a quality signal."
But it is not something that does not help Google. John added "but it definitely helps us to better understand pages, so that we can show them better for the appropriate queries in search."
Here are those tweets:
I don't see it as a quality signal, but it definitely helps us to better understand pages, so that we can show them better for the appropriate queries in search.
— 🧀 John 🧀 (@JohnMu) November 18, 2021
Martin Splitt of Google actually covered this in an SEO mythbusting video but he didnt really say much about it.
John spoke about this topic numerous times - saying that it can help if you to keep "clear structure on a page" but it won't "count it against a site if they improvise / get it wrong," he said years ago. Even back in 2016, he said orders of your tags don't really matter.
Generally, anything you can do to help Google understand your overall site and pages is a good thing. But it doesn't tell Google your page or site is quality by making sure to use good semantic HTML structure - anyone can do that.
Forum discussion at Twitter.