If you want to acquire users from google search its absolutely required that you have fresh and frequently updated content with links from other reputable sourc

If you want to acquire users from google search its absolutely required that you have fresh and frequently updated content with links from other reputable sources to even be considered to be displayed on a search result. If you don't care about acquiring users from search as you have other means then yes a blog may be a complete waste of time. If your site already has some crawl-able content and your already receiving some traffic from google, rather than create a blog your time is probably better spent doing the following: creating more content pages to help google understand your site creating a sitemap decreasing the load time of your site spend money on google ads get high quality back links