A good franchise business will force the franchisee to buy the real estate and give the franchise the opportunity to buy the real estate at a fixed cost (either fixed outright or a multiple of revenue for the location), effectively giving them no downside on capital depreciation on the site (i.e. the value of the site going down) or the ongoing dilaps costs. They only have upside: they can buy the site if it's doing really well. And meanwhile, you're buying your training, goods, services, and paying a portion of your revenues to the franchise.
WeWork is like a franchise which has no interest in owning your real estate.
They and others have realised the opportunity to take advantage of a couple of factors in the macro (more fluidity in working working lives -- telecommuting, flexible work --, startups, low interest rates meaning units can be vacant and on balance sheet without too much pain for an owner) and build a smart offering around that: got an empty building OR bored of the overheads and headaches of managing an office space yourself? We'll lease it from you for a fixed price and then take any upside. You get smoothed cashflow and a fixed yield, and we get whatever upside we can make.
They don't have any of the overheads, complexity, costs, or risks of owning the real estate. The IP and brand they're building (brand is an important factor here!) are not wedded to geography. Shoreditch isn't cool for startups any more? WeWork is gone.