In an era of disruptive innovation, real estate is a laggard. Elsewhere, consumers armed with technology have made an end run around gatekeepers, buying airline tickets, hotel rooms, and even stocks with little to no commissions. When it comes to buying and selling homes, however, a dominant cadre of brokers has made a simple transaction mind-numbingly complicated.

The result: The housing sector remains stuck in the pre-internet past. No other industry is mired in the same dismal combination of opaque rules, minimal transparency, and sky-high fees. In 2021, consumers will fork over $100 billion in real estate commissions — up 16% from 2020.