Nothing in Scripture says that Scripture alone isn’t good enough and nowhere are we instructed to add tradition to it.
It’s only tradition which teaches that tradition must be added to Scripture.
Very convenient, you know.
Because you can't read?
I will ask the Father, and he shall give you another Paraclete, that he may abide with you for ever[...]
the Paraclete, the Holy Ghost, whom the Father will send in my name, he will teach you all things, and bring all things to your mind, whatsoever I shall have said to you
(John 14)
hold the traditions which you have learned, whether by word, or by our epistle (2 Thessalonians 2:14)