Maybe they are but younger Americans tend not to vote in large percentages compared to other demographics. In fact, I think they have the lowest turnout rate in November.
Considering Biden's obvious misogyny (inappropriate behavior around women for years & a grossly anti-women & unconstitutional Title IX policy), single women who pay attention might lose some enthusiasm for him. It's possible the voting numbers are skewed by young men who don't vote while young women vote in larger numbers. I don't know.
A more important group are the so-called soccer Mom's & I can see them turning against Biden, especially if they have daughters competing athletically. Plus, most groups are vehemently opposed to Biden's illegal aliens invasion. Any voter group that cares about the economy, crime, the border, education, and a bunch of other issues will have to take a long hard look at Biden's failures across the board. At least they will if they are honest about these things.
“Incline my heart to your testimonies, and not to selfish gain!”
Psalm 119:36