This happens if everyone becomes millionaire

You should check Zimbabwe's financial position. Their government printed money in response to poor economic output. This caused hyper inflation. At its peak - inflation reached 79.6Billion%:

Zimbabwe had a 100 trillion dollar bill in their currency. In 2008, this was equivalent to approx $3.75 USD:

Homeless people had signs like this:

People had to carry huge loads of cash to make small purchases:

In the 80s the Zimbabwe dollar was equivalent to the US dollar. Imagine you had saved $10,000 in your bank account. This money became about as valuable as pocket lint after hyper inflation.

The lesson here - printing money does not make your economy any more prosperous. Money only has a relative form of value. If everyone is a millionaire, (or trillionaire in Zimbabwe’s case) it simply costs more to purchase goods. The easier money is to obtain, the less valuable it is.