In an effort to demonstrate the insufficiency of scripture, a Catholic once told me "let us not forget that Satan attempted to use the scriptures to tempt Jesus". I pointed out a very obvious fact that is, of course, displayed in that very same scripture: Jesus fought back with scripture.
At no point in history did Jesus ever downplay the importance of the scriptures. Rather, He appealed to them repeatedly with phrases like "it is written" or "have you not read". Neither Jesus nor the apostles ever appealed to traditions to back up their claims. Although there is one verse (2 Thessalonians 2:15) that Catholics commonly cite to defend their reliance upon tradition, the fact is that even this verse backs up Sola Scriptura. This is because in it, Paul tells the Thessalonians to hold to the traditions they were taught either by word or Apostolic epistle. The latter, of course is all scripture. 1 and 2 Thessalonians, 1 and 2 Peter, 1, 2 and 3 John, these are all epistles that started as oral traditions, but are now scripture. As for oral traditions, the fact that they were oral means they no longer exist. We can't listen to people who have been dead for the past 1,900 years.
[Post publication insert: On top of this, early Church "Fathers", such as Irenaeus, taught that it is actually heretics who, [When, however, they are confuted from the Scriptures, they turn round and accuse these same Scriptures, as if they were not correct, nor of authority, and [assert] that they are ambiguous, and that the truth cannot be extracted from them by those who are ignorant of tradition. For [they allege] that the truth was not delivered by means of written documents, but by word of mouth." Read that again: if you think the truth cannot be extracted from the scriptures by those who are ignorant of tradition, you are a heretic. In other words, Catholics, according to Irenaeus, are heretics.]
What we can know for sure is that nothing the apostles ever preached would have contradicted the scriptures in any way. Paul himself declared that if anyone preached a different Gospel than the one he had delivered (by mouth and by epistle), even if it be himself or an angel, that being would be accursed (Galatians 1:8). And yet the Catholic "gospel" is a different one than what we find in the scriptures! The Catholic "gospel" is works based. You must work to earn it, you must work to keep it. And yet, the Bible tells us in no uncertain terms that salvation is by grace through faith, not of works (Ephesians 2:8-9), that grace and works cannot possibly work together for salvation because they cancel each other out (Romans 11:6), and that we can know that we have eternal life (1 John 5:13).
Just as Jesus used the scriptures to defeat Satan in Matthew 4, so also can Christians use the scriptures to defeat Satan in the modern world. We have never had a need for the empty deceit of tradition (Colossians 2:8), and we are certainly to oppose it when it contradicts the word of God (Mark 7:9). That includes when the Catholic Church is so bold as to claim the scriptures which so clearly preach a doctrine contrary to their own are not sufficient for a complete relationship with Jesus. To abandon the scriptures in favour of tradition is akin to throwing off your armour, dropping your sword and picking up a handful of gravel. You're not coming out of that fight victorious.