In fact, it is optimal for ex-ante efficiency to expose banks to liquidity risk, see C. Calomiris and C. Kahn, “The Role of Demandable Debt in Structuring Optimal Banking Arrangements,” American Economic Review,  BIS central bankers’ speeches  3  of last resort, but to perform that function at a penalty rate, illustrates both the need for (liquidity) insurance and the need to safeguard incentives.
Such anchoring is a prerequisite for monetary policy to contribute to economic growth. Historically, interest rates remain low across the maturity spectrum. Thus, our current monetary policy stance remains accommodative, supporting economic activity and job creation.