WeWork started the concept but it has only grown and expanded from there. The co-working or flex space model which began in NYC is fast becoming the new Uber of commercial office space. With large corporations abandoning the traditional work model for more flex space, it is changing how landlords attract and retain tenants.   Recently, landlords are discovering that they can use their building’s flex space as an amenity to attract tenants. Flex space isn’t just a coworking hub: it is bookable meeting space, conference rooms, event space, and…