I don't think you're missing anything. Cash or T-bills are referred to as risk-free because they have very low volatility. That doesn't mean cash can't be devalued - it definitely gets devalued as central banks print more money.
Printing a lot of money should cause inflation over time. If we experience a lot of inflation, precious metals are good hedges. The recent rise in gold is due to many people believing the money printing will cause a lot of inflation.
I'm sure it will cause inflation, I just don't know how much or how soon.