Everyone can be rich, because it's a positive sum game. You having a computer doesn't take it from someone else. Every person on the planet can have one.

It's not a fixed pie. We are growing the pie. Most people in "developed" countries are rich from a historical perspective. We have shelter, running water, cheap and plentiful food (so much that we waste over 30%), electricity, microwaves, refrigerators, pocket computers and so on. There's no reason this can't come to the entire world and continue to improve for all.