They have not really created anything new - at the end of the day they are still just renting out office space (something countless other companies do)
Wework is on the hook for long-term real estate leases, but its tenants typically sign up for flexible short-term leases
If many of these tenants shut down or move during a recession, WeWork is still liable for the long-term leases
If many of these tenants move to other co-working spaces, WeWork is still liable for the long-term leases