“Safe” in this context generally refers only to downside risk. T-bills are safer than I-bonds because T-bills are short-term investments. I-bonds have an early-withdrawal penalty. (I-bonds also have a $10,000 annual purchase limit, but that’s less-relevant.)
No, I am not. Inflation risk is not downside risk.
Inflationary risk is the risk that inflation will undermine an investment's returns through a decline in purchasing power. Downside risk is the risk of loss in value of an investment due to a decline in the price of the security.
Decline in value of an investment because of a decline in the price of the security is not the same as decline in value of the investment because of inflation. Even if the practical consequence is the same.
Inflationary risk matters, and it should not be ignored. But it doesn’t factor into whether an investment is considered “safe,” as that term is typically used in this context.
"But it doesn’t factor into whether an investment is considered “safe,” as that term is typically used in this context."
If you ignore real terms and don't care about actual value (the entire goal of investing), sure. I guess is cash is "safe" too if your ok with losing double digit percentages of your valve over the past 3 years.
