Housing is inelastic enough that they don't need a 100% monopoly to engage in highly monopolistic practices. The article mentions that about 80% of rentals in A

Housing is inelastic enough that they don't need a 100% monopoly to engage in highly monopolistic practices. The article mentions that about 80% of rentals in Atlanta are using algorithmic pricing, and 80-90% of landlords are following their recommendations as is. If the algorithm is laundering their collusion onto 64-72% of the housing market, that's larger than plenty of monopolies that have been broken up in the past.