i believe most of the demand for third spaces is for things that are free to use. parks, places to hang out, activities. these spaces are not profitable.

in germany this is handled by supporting youth organizations. sport, scouts and other activities. most of these groups get free access to government owned buildings. they get financial support for their equipment, etc, under the condition that any youth can join with only a nominal membership fee.

in a pure market economy none of these organizations or spaces would survive. they depend on government support.