Can the injection of new money into the economic system enhance economic growth? Not really. Increasing (or decreasing) the money supply affects the demand for money but doesn't make us wealthier.
Money proper is not artifice. It is a physical "thing" of value, acquired through labor and emerging out of the needs of individuals, who through voluntary exchanges determine its value.
At the heart of Keynesian business cycle theory is the so-called liquidity trap. Contra Keynes, however, economies don't falter because a sudden increase in the demand for money.
The proposed central bank digital currencies are not a new and convenient high-tech form of money. Instead, they are yet another power grab by government authorities, continuing the shameful history of government corruption of money.
As Murray Rothbard wrote, inflation is not an increase in prices. It is, instead, an increase in the supply of money in circulation. The distinction is important.