That's completely counter to how capitalism actually works in practice. With every luxurious technology reserved for the wealthy there are always inevitably improvements in scale and delivery that make these luxuries accessible to the masses. Cell phones, cars, internet access, food delivery service, chauffeurs (in the form of Uber), airline travel, etc all used to be luxuries of the rich. In a short time, prices came down, and became accessible to most people.
Most of the wealthiest people in the world made their billions by selling something used my millions or hundreds of millions of people.
The same thing would happen by focusing on technologies that improve more lives right from the start. Instead of cars we'd be developing better public transit, instead of food delivery we'd be developing ways to deliver food to the people who actually need it, etc. Developing luxury goods and hoping it'll at some point benefit the public is an inefficient way to improve lives.