The $ has been tanking for decades! It already lost most its purchasing power and it will keep losing probably at a much faster rate in the near future!
All currencies are tanking due to inflation, $ is not an exception.
While inflation is normal and we can't fight it completely we need to look at the inflation rate. Dolar in the early 20th. century for almost 70 years kept its value almost on the same level. But now look at the last 30 years. Inflation during that time was higher than in the all years of dollar existence before combined.