said 4 months, 2 weeks ago:
They are very important, for a variety of reason. You should also include the description meta tag in this group.
You can read more here: Why Page Titles Are So Important For SEO
One thing this article did not touch on is how the information from these tags are used in google search results and when people share your content on their social networking sites.
In Google search results the Big Blue Heading link is the content from your title tag, and the description text is from your description meta tag—if the description tag is absent or the content is not representative to what’s on the page google will improvise using text from the page.
In Social media ideally you have included open graph meta tags to instruct what title and description to use, but fallback would be page title and description.
These tags are important in not only communicating to search engines, but also to humans. They should include keywords if possible, but ultimately you should focus on text that entices the viewer into wanting to ready more.