The interest is only a higher valuation of the goods in the present with respect to those of the future. And it does not matter if the interest is expressed in money, because in reality this is only a piece of exchange whose value is subjective, it is by the common agreement of those who decide to use it.
But the interest will always have a harmful effect when undertaking projects and the way to do it is through capital, which is the product of saving what has been earned through work. The rule is simple: when interest rates fall, there will be more resources to invest. When interest rates rise, resources are not available to invest.
This means that central banks always depreciate the value of the money they print.
Thus, the more depreciated the money is because interest rates are higher; on the contrary, money is worth more when interest rates are low.
As the money is depreciated, the central bank prints more money and inserts it into the market, money that, of course, has no support whatsoever. This makes all the money then have the same depreciated value, which manipulates people not to save or invest more; but rather, consume, spend the money. Some few make the intelligent decision to buy more supportive money (stronger foreign currencies, precious stones or metals or cryptocurrencies) but most prefer to spend on consumer goods, which contribute little to growth and investment.
Of course, this again causes interest rates to rise and new issues of money flood the market.
