On desktop platforms, nearly 10 percent of all pages loaded are from the forward and back buttons. Mobile use bumps this stat up to 19 percent of page loads. If Google can pull off this feature well, browsing will appear to be far more responsive and seamless than ever before.
Building out better caching mechanisms will help improve battery life on portable devices. However, a caveat of more caching means more memory usage. Chrome is already often criticized for devouring RAM as soon as a small handful of tabs are open. Storing dozens of web pages in a new cache will required even more memory.
Chrome's "bfcache" feature is under development now and is not expected to make it into stable versions of the browser until 2020.