Because it is financed using future profits, which allows the economy to develop faster, but on credit.
You mean the interest paid on top of a loan?
This is a side effect that occurs due to the increase in the emission of money. The more pieces of paper circulate in the economy, the less valuable each individual piece of paper becomes.
But my question is how? What is the mechanism in the background that determines this? Who or what decides that your fiat is now less valuable against BTC, gold, and other currencies? Who keeps track of it? The same institutions doing the printing? Why would anything they say be trustworthy?