Yes, risks and benefits are in direct proportion. The higher the risk, the higher the expected return. Conversely, the lower the risk, the lower the expected return. Medium and low risk funds generally refer to bond funds, which mainly invest in bonds. Fund risk is determined by the bonds invested, and the risk of bonds is low, so the risk of bond funds is relatively low.
Bond risk mainly lies in default risk (bond issuer can't repay the principal and interest on time), interest rate risk (interest rate rises, bond price falls) and purchasing power risk (inflation leads to currency purchasing power decline), and bonds are generally less risky and relatively stable.