Hey,
You can certainly have a successful coworking community with 6,000 SF. It’s more about the location, your market positioning, and what your goals are. If your goals are to become rich, then 6,000 SF might be a bit small no matter where you are. However, I’ve successful had spaces as small as 3500 SF. My goals were never to get rich off of them, but have a few great neighborhood coworking spaces that support my lifestyle.