Wealth is stuff people want.
A "wealthy" person owns economic engines that deliver this stuff to people who want it. How wealthy they are depends on the number of engines, how much stuff they produce, and how much this stuff is wanted.
Why is this relevant?
Because no matter how fast technology progresses, we can survive if we understand how to create wealth (in the technical sense) from scratch.
Most of the time, we work in exchange for money.
But it's really important to understand that money is not wealth.
It's just an intermediary. A way of transferring wealth from one specialised category to another.
When a lawyer gets a knee replacement, he doesn't pay the surgeon in tax returns. Instead, he turns his skill of writing tax returns into money, and then turns that money into a surgery.
Civilisation is built on exchanges like these.
And to properly understand them, we first need a reality check.