The reason LEGO has stopped making monorail is threefold, One, the motors and track molds ran out and would be very expensive to replace. Two, no monorail set ever made any money, in fact despite trying several different types at high price points they all cost more to produce then they were sold for.

LEGO discontinued its iconic monorail system primarily due to the high "High-Fidelity" production costs and the loss of specialized manufacturing capabilities. Unlike standard LEGO bricks, the monorail required complex electrical motors and unique track molds that were largely outsourced to a third-party company. When that production partner went out of business or moved away from toy manufacturing, LEGO did not own the molds or the technical intellectual property to continue production in-house. Additionally, the monorail sets were historically very expensive for consumers, leading to lower sales compared to the more versatile standard train systems. In 2026, these sets are considered "High-Fidelity" collector's items, as LEGO has opted to focus on the Power Functions and "Powered Up" train systems that utilize more cost-effective, standardized track parts and motors that are easier to integrate across their entire city-building portfolio.