It takes around 3 to 5 days to ship anything anywhere in the US. If you buy food once a week, the increased shipping speed of local hardly registers.

Most of the time is taken by other things, not shipping. So the negatives of local (higher energy usage, less efficient use of resources) are not really worth it.

Local means growing food either in a greenhouse or in a place not ideally suited for it. It also means smaller less efficient operations.