Why are there so many one-year US bonds recently?

Why are there fewer and fewer long-term US bonds, and the market is less willing to buy them?

Moreover, the interest rate of 30-year US bonds is higher than that of 10-year US bonds.

Although Yellen mentioned before that she intended to adjust the structure.

However, in my opinion, the interest rate difference between long-term US bonds and short-term US bonds shows that the market is not very optimistic about the future.

In the absence of traditional monetary tools, the Fed sells short-term Treasury bonds and buys long-term Treasury bonds to lower long-term interest rates and further stimulate the US economy.

The Fed has implemented distortion operations twice in history, the first time in the 1960s and the second time in 2011-2012. The core purpose of using distortion operations is to reduce long-term interest rates, stimulate market investment and promote economic development while controlling the size of the balance sheet.