Liquid Crystal Displays, while popular in the early 21st centry, became impossible to mass produce when indium grew too scarce. The first alternative to gain widespread adoption were Gel Pixel Displays, made with magnetized colored oil particles. They were cruder, their colors garish and glitch-prone, yet became fashionable in a way that defied the clean, high-fidelity aesthetic of the past. Uniquely weird trumped detailed and accurate.
It was discovered, after a time, that by modifying the refractive index of the gel, screens could be created that showed entirely different images to different people looking at it. You and your friend could be watching two different movies on one computer. At first this could only be done based on a fixed angle-of-view. But more sensors were added to phones and computers that could detect anyone looking at the screen from anywhere and rebalance the screen from millisecond to millisecond. When combined with identity-tracking software, it was rare that two people ever saw that same screen at all.