If glucose was used in place of fructose it would get used up very quickly as it has a high glycemic index but fructose has low glycemic index and gets used up slowly by the spermatozoa so that they can survive for many days (upto 3) in the females body for successful fertilization.

Another reason is that the metabolism of sorbitol into fructose is energetically efficient way (no ATP required) as compared to glycolytic conversion of glucose into fructose(G→G6P→F6P→F).

Seminal fluid contains up to 11 mmol/L (200 mg/dl) of free fructose. It is the major energy source for the sperm cells in their all-important race for the ovum. The advantage of fructose over glucose may be that many bacteria, which compete with the sperm cells for the available nutrient, prefer glucose to other energy sources. Thus, to avoid other competitive bacteria and cells from utilising the energy source of sperm, fructose is used as the energy source since the bacteria prefer glucose.

Highly appreciable👏 can you please provide references