This is very much like the liberal "Don't give Trump attention and he'll go away" belief.

By not talking about Biden's age, maybe you will feel comforted that it's not an issue, but a not insignificant portion of the voting public very much believes that it is an issue.

Many people voted for Biden over Trump to get Trump out of the White House, believing (falsely it seems) that both men would not be back in 2024 because of their age. Unfortunately both are back and age IS an issue, this time for Biden doubly so because he's the incumbent.