Better technology and safety
You get what you pay for, as the saying goes. Luxury models, while more expensive, are at the cutting edge of technology. That means you can expect premium audio systems, more advanced and user-friendly infotainment systems, more innovative features like memory seating and hands-free liftgates, and, most importantly, out-of-this-world safety technology.
Cadillac, for example, is at the forefront of the autonomous driving movement. Its Super Cruise technology is the closest thing we have to self-driving cars; thanks to a range of advanced safety systems, Cadillacs actively work to prevent accidents, even when the driver makes a mistake. These technologies are typically several years ahead of the technologies you'll find on mass-market vehicles.