Earlier quoted context omitted.
This article literally says, "The central bank created new reserves out of thin air" the premise of the article seems to be more about taking issue with the fact that the "money printer go brrr" meme popularized in the media doesn't tell the whole story and over simplifies the mechanism. The key point is that when the Fed buys a bond from an investor that investor has cash which they can then take an buy something el…
The issue with reserves is that they are not money, they have no way of getting into the real economy, they just sit on bank's balance sheets. At the end of the day, its up to commercial banks to create new, spendable money. The whole reserve thing is just to incentivize them.
When talking about money and banking, the word "money" is useless at best.
Reserves, Federal Reserve notes (i.e. paper money), coins, deposits, Treasuries, commercial paper, gold and wampum are each money. Central banks converting Treasuries and mortgage-backed securities into reserves lets commercial banks create deposits at greater scale. That ceteris paribus increases aggregate demand which can put pressure on broader price levels.