As pagan practices were incorporated into the early church, they became a system of works, rituals, sacraments, etc., that substitute for the Gospel of Grace.
That the claim is made that Ash Wednesday celebrates Genesis 3 is simply a claim from a later time to backfill a practice incorporated from paganism. It is neither commanded to the Church, not instructed, nor modeled, nor written about before 100 AD.
You can believe this is you want. That's fine. Paul praised the early churches for the good order. Their good order was adiaphora, neither commanded nor required. These acts do not replace grace. These rituals provide good order.
If someone says that these rituals or works replace grace, I will join you in their condemnation. But these rituals and structures are not forbidden or inherently bad.
It is neither commanded to the Church, not instructed, nor modeled, nor written about before 100 AD.
I don't think you properly understand adiaphora. The church is allowed to do thing not commanded nor instructed.
Formula of Concord: X. Church Rites, Commonly Called Adiaphora.
Therefore we believe, teach, and confess that the congregation of God of every place and every time has, according to its circumstances, the good right, power, and authority [in matters truly adiaphora] to change, to diminish, and to increase them, without thoughtlessness and offense, in an orderly and becoming way, as at any time it may be regarded most profitable, most beneficial, and best for [preserving] good order, [maintaining] Christian discipline [and for eujtaxiva worthy of the profession of the Gospel], and the edification of the Church. Moreover, how we can yield and give way with a good conscience to the weak in faith in such external adiaphora, Paul teaches Rom. 14, and proves it by his example, Acts 16:3; 21:26; 1 Cor. 9:19.