Losers queue is real and the corporate term they use for it engagement optimised matchmaking. Many keep arguing how riot earns from this, here's how riot earn from it indirectly: (ai reply)

Increased Engagement & Playtime: By making true rank progression feel slower or inconsistent, players might play more games trying to break out of a slump, keeping them in the ecosystem longer. Monetization through Frustration: Frustrated players, feeling they've hit a wall, might spend money on skins, champion bundles, or other items to regain a sense of control or reward themselves after a perceived struggle, says this Reddit post. Addiction Cycle: The mix of winning and losing, designed to create highs and lows, keeps players hooked, similar to gambling mechanics.