The standoff is to keep the wood off the concrete. Typically building codes do not allow untreated wood to be in direct contact with concrete and want at least 1" separation. We call for either 1" metal standoff base or a treated 2x cut to the post size and screwed to the bottom. The treated 2x is a cheap way to handle things, though not pretty. If you are okay with putting base trim around the bottom of the post, you can cover up the 2x that way. The concern is untreated wood in direct contact with concrete will wick moister and cause the wood to rot.
This forum is a phenomenal place and an incredible resource. Good luck with your project.
