Notice that proponents of Sola Scriptura, when pressed a bit, admit that it’s no such thing as Sola Scriptura, and they don’t like their admission one bit.
Notice that no Catholic understands, or will accept a non-Catholic’s definition of sola Scriptura, no matter how many times it is explained to them.
Catholics just love tilting at windmills.
*It is written...* is all we need to know and being the divinely inspired word of God, is inherently authoritative, not needing any one’s stamp of approval to make it so.
As such, it is reliable and adequate to THOROUGHLY equip the man of God. It is sufficient to bring us to salvation and maturity in our walk with Christ.