TIPS "treasury inflation protected securities" currently provide very little upside (return), but that exact statement can be made about just about any area of the fixed income market. Where they do present a potential opportunity is in relative terms against traditional Treasury bonds. Regardless, this post is less about the opportunity within TIPS and more about the return profile they provide. For a deeper dive into how TIPS function, I recommend this Vanguard piece.
TIPS also provide some deflation protection to the principal (but not to the coupon payments). At maturity, if consumer prices have fallen so much that the inflation-adjusted principal would be below par, the Treasury will repay the principal at par value. In this manner, TIPS provide a “deflation floor.”