"For the creation was subjected to futility, not willingly, but because of him who subjected it, in hope". ESV.
If Adam was not asked before it happened if he would like to be in a garden, tempted to disobey God, and not given the grace to obey; if all of this was imposed on him, then that might be the meaning of "not willingly". i.e. it was imposed on him.
Or, if Adam did not want to eat the fruit out of respect for God but scared of what refusing Eve's suggestion might do to his relationship with her, then "not willingly "might mean "scared and so willing".
One issue, it appears to me, is first to be clear what "futility" refers to. If it was futile thinking on Adam's part to consider that disobeying God would be to his advantage, then futility has entered creation. Adam and Eve realise that their lives are empty, vain and foolish which they try to hide in Genesis 3:7-8.
Adam and Eve compound their initial futile [vain-mataioteti] act of disobedience by trying vainly to cover up their shame with leaves and hiding. Thus vain futility is established in creation before the curse of Genesis 3:17-18.